Binders

This is my first time posting here, and I don't really like it, but I figured it'd be more appropriate here than in the general ala discussion board.

I'm gender neutral, and recently started wearing a "binder". Quotes are there because it's not quite a full binder - it's a binding bra from Underworks. It doesn't get me completely flat, but it works well enough with layers, which is great.

Except that even after just around 3-4 hours of wearing it, sometimes less, it gives me absolutely unbearable back and rib pain - and it isn't even that tight. Do any of you who have experience with binders have any suggestions? I'm looking into getting a full binder as well, so any suggestions for that are nice, too. I've had to take a 2-3 day break just so I stop hurting.

It's unfortunate, because my body is unfortunately very sensitive to pain (mixed with high pain tolerance, but my body reacts very negatively to even small things - if I rub my arm too hard, it'll feel like it's bruised for quite some time), but I'm much more confident and comfortable with a binder, so I feel like I have to choose confidence + pain over panic and discomfort with my chest.