So, first step! Identify when you're feeling hamstrung mentally by abuse you survived when you were little.
Second step: if you're feeling awkward being open or affectionate because of the above, examine it.
Dissect it. Once you understand your automatic reactions, you can start to edit them.
Third step: Fuck up. And I mean a Lot. If you're on the autism spectrum, this part's gonna hurt like hell. Try and find other folks who'll understand that you're still on the third step.