I've measured myself a ton of times and usually get different measurements each time, and then when I get a measurement that's constant, I put it in online converters and it comes out differently. Then I had my mom help me measure, and it says I'm a 34B even though I've worn that size and felt like it needed to be a bigger band size.
I trust her measurements enough to not get it done "professionally". I don't want to get measured by anyone else because I hate people being close to me like that.

So I tried on like 6 bras the other day and found 2 that felt like they fit well, but now that I'm wearing them, they're killing me!
When I tried it on, there was no space in the cup, but now it's like the bra is jutting out at the top of the cup and there's like almost a centimeter of space.
I know that the band has to lay flat on your back. If I adjust the shoulder strap to where it feels right, the band isn't flat.
It feels like I'm being constricted, no matter what stop thing I have it on the bra, and it felt like that when I was wearing 36/8 B too. It feels really wrong and causes me a lot of anxiety, and feels like I get short of breath.

My ribs are sensitive and are slightly misshapen, so that might contribute a little? It really doesn't help that most of my clothes don't fit or are uncomfortable and cause me a lot of anxiety and anger! I almost feel like crying with the way bras make me feel SO uncomfortable!

I can't go around in public without one because I'm self conscious about my boobs, plus I HATE people noticing and blatantly staring. Those sticker things for nipples don't work. Sports bras make me look even more flat chested and they're super uncomfortable.

Has anyone else dealt with something like this? Can anyone give me any advice without telling me to get "professionally fitted? Because that's never gonna happen.