My FIL is an absolute shit to me, but he's not much better to his own son: controlling, judgmental, petty... One of my girlfriends has the same thing going on with her out-laws. Don't make a decision about your marriage while the old goat is still in your house. Wait until he leaves and then see where things go after you and your SO are alone again together. Can you get your relationship back on track?
One thing my girlfriend and I realized early on, was that our partners needed protection from their own parent more than we did. As inlaws we were not emotionally invested in their approval, nor did we have the bonds of love to be manipulated by. It's pretty hard for children to give up on their parents.
Once you and your SO have alone time again, you two need to talk openly and honestly about setting boundaries with the FIL. It may be as simple as he's no longer welcome at your table, nor will you eat at his. That's worked for my girlfriend. She has almost zero contact with her inlaws and her husband supports her decision. And after he visits with them, she's there for him when he comes home upset after being emotionally wrung out because that's what his family does to him.
As for me, I've developed a working relationship with my FIL. My SO rarely visits unless I go with him. That's my SO's choice, he could see them every week for all I care, but he finds them hard to be with without me there to protect him. FIL learned not to fuck with me, my husband, and then my children. I never raise my voice, or cry and will always call him on his bullshit because I don't give a shit what he thinks of me. And. He. Knows. It. But that's just me and my personality and not everyone could do that. I've dealt with bigger pricks than him on a regular basis at work.
You'll either be able to work out a plan with your husband on how to deal with his father in the future, or you won't. But right now is probably not the best time because you're in the middle of ugly times and don't have much privacy.
I've seen marriages break up because of interference by in-laws. I've seen some last in spite of the in-laws. There is no right or wrong answer for you and your husband, but you do have to reach an agreement on how to deal with FIL. One that both of you can live with without feeling anger and resentment.
I wish you all the best.