we werent going out but now i want him back

i ended things with the guy i was going out with a few months ago, we then sorted things out and were almost back to normal. then i went to spain for three weeks and returned to hear that he was with a new girl. we weren't actually going out at the time so he didn't really do anything wrong. hes now broken up with the girl and i want to try and get back with him again. what do i do? thank youuuuuu

Just start talking to him again. Any guy with a head on his shoulders will realize that's a green light

Thanks but I don't want to seem needy?

I've lost dating with women because one or both of us didn't want to seem "too needy". Which lead to one or both parties holding back and just thinking the other person wasn't interested, was lazy, or just didn't think the person was important to them.

This is what needy is, sending multiple texts without getting any responses back, demanding why someone hasn't contacted you within THEIR expected time-frame, needing to be with someone all the time, etc.

You're messaging the guy once. It's not needy, its going for what you want.
When I'm in positions where someone unilaterally changes the terms of our relationship or whatever, I just speak my mind, I say things like "It really felt great whenever I was with you, I would really like to see you again so just let me know if you ever feel the same"
It's not needy. What would be needy is if I said this and kept contacting said person instead of waiting for them to get back to me.

You haven't made it clear what you want, he might think you're just not interested or have moved on.
Make your intentions clear.

I realize you probably don't feel comfortable doing that, so maybe you can just try initiating contact with something simple

Go contact him and ask him out. That's not needy at all.