MIL's and FIL's do not see the errors of their ways in raising children because more than likely they were raised that way themselves. The way that your MIL handled your son's grades was unemotional. She didn't validate what your son accomplished in school. You, his mother, where elated w/his grades and you let him know that you were proud of him. I can see where your h wasn't validated/recognized for his efforts and the only time she gave him the love and attention he needed was when she complained about what he wasn't doing right in her eyes. To her, that was her love language, i.e., to complain.

I'm glad your h came over and helped you out for a while. Definitely be sure to tell him how much you appreciated it. In fact, a nice text today to thank him would go a long way and then again in front of your son. This way they both get to see what recognition is like. I know you praised your son in front of your h, but it also will be good for your son to see Dad get some praise too. By doing this, it may alleviate some of the tension and resentment on your h's side of things w/his son.

I'm also glad to hear that the taxes are going to break even this year for you and your family. Every little bit helps when it comes to tax time.

So, what are you and your son going to give H for his birthday? I'm sure you will think of something really nice that he can enjoy.

Enjoy your Sunday!

Sit quietly, the answers will reveal themselves when you least expect them to.
The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.