It is. For me anyway. But can you share some of that "attractive peeple showing interest in you often" with me because I experience the exact opposite and that's taking all of my hope for life away... I didn't think I was that fugly but I guess I must be. So it's not like I'm qualified for giving any advice but since I thought of possibly helful stuff, here you go anyway.
Anyway it's easier if it's a themed bar based on something you're interested in, for instance a gaming bar, where you can have an excuse for interacting with people / are put in a situation where you interact with others during games, meetings, whatever.
In a normal bar I have dreamed of brainwashing myself into just being natural with people and talking with them freely without taking my self perception in consideration at all (might be ruined by my fuglyness or awkwardness but might work otherwise). Maybe start by asking if it's ok to talk to them in a friendly way, just focusing on appreciating other people and not on yourself at all.
Now I've been dying too much to try it out but in some places like associative bars people might be more open to a direct approach and less judgemental overall. Otherwise maybe try to sit / stand next to someone and find an excuse to ask them something then start a conversation.
The point is to try and forget yourself, at least your trauma, past negative experiences, maybe get to a point where you feel decently confortable with yourself if you can but focusing on the place, the experience, and the people more than yourself can help take the anxiety away and make you more natural and friendly.
Hopefully that can help you feel less stressed about it.