Hmm I understand you feel trapped and feel like you can't get out of your in laws' house, but where there's a will there usually IS a way. I don't know exactly where you live or how much rent you'd be spending on a place. Nor do I know how much your husband makes or how many debts or whatever you have to pay off.
However, is there a way you could get a job and contribute to your family's income? Perhaps you could try working from home or doing something freelance? Even just a part time job would get you OUT of the house and help you earn some additional income.
And okay, even if you can't afford your OWN place, could you rent a room somewhere else? There are other families renting out rooms or parts of their own homes to young people and couples, and probably wouldn't charge too much rent. Sure it's not your own space, but it's away from your in laws!
As for the rest of it, I do understand how you feel, because I'm also a bit of a people pleaser (which I hate about myself). I also hate the idea of people talking or bitching about me behind my back. It really upsets me!
However, I have also realised that it doesn't matter WHAT people say about me. It really doesn't. Last year I moved to the country with my husband to work in his parents Roadhouse. BAD MOVE. I hated it. His parents were ALWAYS talking to him about me, what I was doing wrong etc. etc. etc. In the end I left and moved back home (my husband is still staying with his parents...). He accuses me of running away. Whatever. To me I was saving my sanity! I didn't quit my job and move away to be treated like an imbecile. Now, I KNOW that my in laws talk about me behind my back, but I'm learning to let it go. If they don't like me SO WHAT?
The problem is in YOUR response to it. Really, some people won't like you. That's a reality. It's something everyone has to deal with. It doesn't affect you unless you let it affect you. I know it's much harder while you're living with them, because it's right in your face. At least now I'm away from my in laws and what they say about me 130km away can't really touch me all that much now
One thing I HAVE learned is that no matter how nice I am to other people, no matter how I try and please people and do the right thing, people will STILL dislike me, and they'll STILL say things about me behind my back. So why not just be true to myself and stop being so bloody nice? I do still struggle with this, but I am getting better! I can now say "No thanks!" to telemarketers without breaking into a sweat (I never used to answer the phone unless I knew the number of the caller in case it was a telemarketer and I ended up buying something I didn't want or need, or ended up donating money I don't have etc. etc. because I couldn't say NO). I'm not perfect, but I'm getting better.