Don't be sorry! You're going through a lot and I'm happy to lend an ear! It's difficult to know the best advice to give without knowing all the people involved, so I'm not sure if this will be helpful or not but...
I have had this issue with my husband, too, where he doesn't see his behavior as a big deal, or will say, "I'll try to do better" but then puts no effort into it. I decided to put it in simple terms for him: if I have a problem with something he does that he has no conviction over, he should respect my perspective and work with me to fix it. That is what being a supportive spouse is all about. You have told your husband that you are concerned for your future because of his behavior and he is not respecting your perspective by dismissing your concerns and ignoring your request. By not taking you seriously, he is already proving your concerns valid! I told my husband, "I have explained my perspective to you in very clear terms. I'm not being unreasonable. I am not asking you to spend a bunch of money. I am asking you to change your behavior because it is hurtful and rude, and even though you don't care, I DO, so if you love me and respect me, you will work hard on this because it matters to me." And to his credit, he did work on it. It wasn't an overnight change and it isn't perfect, but he's made a lot of progress. I offered to help him work on it with gentle reminders if he promised not to get annoyed or ignore me, and that helped us both. Maybe if you lay it out for your husband like that, he will be more willing to consider his approach. Or maybe you already have and it didn't work out.
I have found that as long as I make what I want and/or expect from my husband super clear, he is usually really responsive to it, even if it takes him a minute to get there. Hopefully, your husband will be, too. You are newlyweds, and that first year introduces a lot of changes and friction, but in the end, you married because you love each other! Hopefully that means that he will be willing to work it out. It just might take him awhile to get there.
As for your mother-in-law, I'm afraid there's no easy answer. I think you have to make it clear that you want to be part of the family and that you respect her house, but that you come from a different environment with different expectations, and that you have to draw boundaries for your own happiness. You have compromised a lot by joining his household and changing many things about your life to be a good wife, daughter-in-law, and worker, but it's not right for you to compromise everything, or to be the only one making compromises. I know it's hard to draw a line with in-laws, but the earlier in the relationship you do it, the easier it will be to create a new and healthier dynamic.
And definitely inform your husband that you need him to support you when it comes to her and not tell you useless advice like "ignore her", because obviously that's not possible. That's just rude! She's family now. Besides, when there's turmoil, women tend to carry it around with them, adding stress and anxiety to our lives when most men seem capable of ignoring it when they don't have to deal with it. We aren't like that. It's important for him to understand that and support you the way you need to be supported, not the way he thinks you need.
Anyway, I typed a lot... Sorry! >_< I'm doubtful that any of this was very helpful, but I'd be happy to listen and chat with you anytime you need it! I really hope that you will be able to find a solution that works for you and makes you happy. It's a difficult situation to navigate and I'm really glad that you have a place to go to get some space instead of being trapped in an uncomfortable situation. And I'm really excited that you are able to get some work on the game done! It's something you love to do, something positive to focus on when things in your personal life aren't going the way you planned. It's good to have that. I'm cheering you on!