My question is- can you go back and get Ed-e from Ulysses's Temple if you left him there at the end of Lonesome Road?

There are 2 ED-E's, one will stay in LR and one who's waiting for you in the Mojave (with the upgrades you got in LR though). If ED-E is still alive, you can probably go get him to travel around the Divide, but he won't follow you back to the Mojave, if that's your question. I've never finished LR with ED-E being alive though lol Well, I only finished LR once. So, yea. lol

I didn't rescue him at Ulysses's Temple at the end and I'm wondering if I can still get him so I have a companion in The Divide.

No you cannot. He is destroyed because you left him.

Well I went back to Ulysses Temple and he is trapped in a repair pod or something like that, can't release him with the computer, svcks because I wanted to save him but I accidentally went in the area where Ulysses was... Well that kinda pisses me off....

Lesson learned I suppose