Your guy's Mom is constantly on your mind. You sound obessed. For someone who doesn't care what she thinks about you, you are certainly thinking about her a lot.
The previous poster suggested that both of you NOT tell your Moms about your fights and I agree with that 100%.
If you are truly happy with this guy, then focus on him and stop dwelling on his Mom. If she likes you, she likes you. If she doesn't like you, nothing you can do or say will change her mind. But if you marry this guy, you will also "marry" his family, too, and you need to think long and hard about that.......