I know the feeling. I am female, so tend to make more of an effort to fit in, but I do have a history of social faux pas, usually due to trying too hard, or repeating behaviour that has worked well in the past or worked for other people in different settings. Your best bet would be to ask someone you trust what you're doing wrong, and try to rectify that. Do one thing at a time, and don't let that person bombard you with a long list of things - if they don't know about your condition, then tell them (if you're self-diagnosed and feel uncomfortable announcing a condition that you haven't officially got, you can say you believe, or think, you're autistic). You can explain some behaviours as struggles, for example, you struggle with crowds, cannot hear conversation if there's a lot of background noise, have trouble remembering what has just been said, etc.
If large groups, or a lot of noise, for example, are too much for you, find small group, or just hang out with one friend for now, but do avoid becoming clingy, or you'll alienate them; go somewhere quiet, even if it's only a café, for a short period of time. Or go for a walk together. Then make it a threesome. Try to avoid monopolising the conversation, repeating yourself or dragging it back to your favourite topic. If you do make a mistake, don't beat yourself up about it and try not to get obsessive about it (easier said than done, I know); but be aware of it next time and try not to do it again.
It won't be easy, there are no quick fixes I'm afraid. Just plod on and work at things at your own pace. When you do get something right that you would have got wrong before, don't go on about it to your friend(s) or you'll sound childish, but do pat yourself on the back.
