As Beckamaw says - he/they have a massive inferiority complex. They really do. That's why they are spend, spend, spend with their new money. That's why they bully you - they are jealous of you, of your background, your upbringing, probably your education (?).
You said as well that you're "the strong loud one in your family". More reason for maggot to be jealous, not only have you all the above going for you, you are also apparently confident, outgoing, happy, tough (the fact that you don't feel like that inside at the moment is not the point, you started out like that, and probably still give the outward appearance of that). Add to all that, your lovely figure, being a genuinely nice person (ie not a bully like them), great family, fabulous husband etc, etc.........well, you can see why they might feel threatened by you, can't you?
Just remember that as much as you appear "strong and loud", and you feel that you're not, his self-confident exterior is almost definitely not real either. He just simply wouldn't act like he does if he really was as his persona suggests.
I so agree with the posters who have said that you are too involved with them. Go minimal contact, just as you would with any other toxic person in your life. Hi/bye is perfectly adequate for conversation at handovers. Or maybe ask someone else to hand over your daughter for you. Don't accept their "gifts" (poison chalices, more like), and likewise don't buy anything for them, ever. Don't have them on FB, if you have it. Don't reply to texts unless absolutely essential. In other words, don't give them the means to get to you.
I think in the long term this approach would be better for your daughter too, because as she gets older she will be hurt by their treatment of you (she will see through your false laughter) and they may well start on her too - that's just the way this type of people are. She needs to see by example that it is ok to back away a little if she needs to.