Maybe take some beginner lessons? I think it could be a lot of different things, a good teacher will quickly show you what to do and save you lots and lots of frustration.

I wish I'd taken that advice, like I've played guitar about 10 years on my own and built up a lot of bad habits, I finally had to go to an instructor to unlearn them...I still am.

I found what helps with barre chords for me, is maybe starting off with partial barre chords and you'll build up strength. The thing with guitar is that you don't need to be THAT strong to play, it's more about coordination. So if it's hurting your hand, there could be some issue other than finger strength.