In laws trying to trap us

Ok so long story short we had to move in with my in laws they told us to help with the bills when we can. But they don't try and help us with anything other than watching my son. If I needed a ride to work it is a big deal. Today the issue was his check came in late due to ups and our car payment was due. So I asked if I could borrow The 350 and I would put it right back as soon as we got the check. Her response was give it back you can't afford it! But she is always on my brother in law to make sure he gives her money for something he got on her credit card. Like why is it ok to mess up my credit but not yours? Not to mention if I don't have a car I can't leave and they are awkwardly obsessed. They haven't seen their oldest grand daughter in 3 years but they won't give her belonging (old clothes that don't fit, a bed and stuff for an entire room) to someone that could use it... We were supposed to stay for 2 weeks but everytime we go look at an apartment his father finds something wrong with it and the hubby agrees... 
Am I overreacting?