Evil Enderman(Wither?)/Nether Portal help

[RobinHood3]

Hey guys, I need a little help here in my survival world..
Recently created my first nether portal in the world, went down, luckily had it spawn in the middle of a nether fortress... I secured the portal in a cobblestone housing thing with only one exit, venture out, thinking all is well, I gather some netherrack, come back to the overworld, make my first cauldron, am enjoying life, etc...
Decide to go back down to the nether to get more resources so I prepare a little better, enter the portal, and immediately upon spawning am faced with an evil spider and Enderman, both of whom attack and kill me in less than 3 seconds (before I even have a chance to realize what's going on - it took me a second HCSpawn and a second trip through the portal [with nothing in my inventory this time, I was prepared to die] to figure out what happened).
It happened the second time too.
I'm being promptly murdered by an Enderman and a spider as I go through my nether portal now. Any tips? Is there any way to clear the other end of the portal, or should I just build a new one? I'm not advanced enough currently to take them on (I don't have enough iron for armor or anything at this stage). I don't mind getting more obsidian and building a new portal elsewhere, it would just be a pain in the rear... I need advice. Has this happened to anybody else? I've only pissed off one enderman so far this game and that was about 2 weeks ago at a different base, so I don't think that's the same one that's down there... I have no idea why he's mad at me and/or how to get rid of him. They're literally waiting for me IN the portal as I go down.
Thanks for the help in advance...

**P.S. upon further reflection, it may be a Wither Skeleton waiting for me rather than an enderman, since neither time upon traversing the portal did I get longer than a 2 second glance through the portal. I just have no idea what's going on, and no clue how he got through my 2x1 doorway into the portal room in the nether if it is a wither thing.**

***PPS I can't figure out why there's a spider there either, given that the room has a 2verticalx1horizontal entrance... unless he traveled THROUGH the portal? It's in the open in a desert, maybe that's my issue. Perhaps I should seal up the overworld entrance... Again, any advice is welcome!***

[TheGreatIntelligence]

Mostly likely what happened is a spider and an enderman wandered into your portal from the Overworld and were waiting for you on the other side. You should build a shack around your Overworld portal to keep mobs from entering it.

[RobinHood3]

Thanks for the quick answer... that's what I was afraid of. The whole mobs-entering-portals deal is new to me, I haven't played in a long time. Is there anything I can do to get rid of them in the nether, other than building an entirely new portal? I simply don't have time to kill them as I go through, I'm dead before I can really see what's going on. I'm definitely going to seal the overworld entrance now.
Thanks!

[RalphKastro]

I rememeber something about wither jockeys, but I don't remember if they're possible in survival.

but yeah, they probably wandered into your portal and ended up in the nether. You could try to take them out, but I don't think you have the iron needed to do that(endermen do 5 hearts damage per hit, so it would be pretty tough)

Edit:Ninja'd

[TheGreatIntelligence]

Um... I can't remember if TNT carts are in 1.5 but if they are then try sending one through the portal while ignited. That would hurt/take out the mobs, along with your portal, shack and part of the fortress. But fuck it.

[RalphKastro]

Um... I can't remember if TNT carts are in 1.5 but if they are then try sending one through the portal while ignited. That would hurt/take out the mobs, along with your portal, shack and part of the fortress. But fuck it.

even if they are, that would need a trip to The End

[Rob]

This would be willingly sacrificing tamed wolves. But, I'd suggest bringing a few with you to guard you while you are spawning into the nether. They should keep the enderman and spider busy long enough for you to get your bearings and defend yourself. You could probably bring the wolves back with you if they survive. There shouldn't be anything to worry about. :P

[RobinHood3]

Thanks everybody for the comments! Working my way back to my main base from a far spawn off in the middle of nowhere now so I'll definitely try the wolf thing... Otherwise, it looks like I may be building a new portal. Was unaware things would crawl through and ambush me on the other side, so I'll have to build a little hut around the portal now!
Haha. Thanks again to everyone :)

[EtherealWrath]

You might be able to get them back out into the overworld.

Travel a long way if you take the second portal route; otherwise you'll merge into the first one.
(at least a half day assuming flat/easy walking)

[RobinHood3]

Is it that far? I know 8 blocks = 1 block in the nether, but I didn't know I'd have to go that far... Either way, I don't think I'll need to!
Good news/progress update! I made it back to my base and went back down to the nether more prepared this time and took out the 2 spiders that were assaulting me - the Endermen (2 of them!!) are not actually mad, they're just there chilling. With roughly 4.5 hearts of health (?), I gathered my belongings from the last 2 trips and came back into the overworld, where there was a skeleton waiting to attack me (-.-).
In the process of hobbling away, HE went into the portal, meaning now I have another surprise waiting....
I gathered a pile of sand and blocked off both sides of the overworld portal though, so hopefully I can build a structure around it with no more surprises than the skeleton waiting for me.
Thanks for all the help guys!

[RalphKastro]

If I remember correctly, endermen pick up Netherrack, so they should leave in some time peacefully, if you don't stare at them

[Yhetti]

You could probably bring the wolves back with you if they survive. There shouldn't be anything to worry about. :P

Okay this is mean...

You should build a shack around your Overworld portal to keep mobs from entering it.

A quick and easy way to do this is to just make a little ring/fence around the outside of the portal, made out of something that endermen cannot pick up.
I neglected doing this for a long time and (my portal was in a swamp) there were gobs of mobs (unintentional rhyming) at the portal when I entered, witches, creepers, spiders zombies, luckily the creepers blew just about all of them up except me.