The arrival of a child changes everything. It’s normal to struggle some with who should visit and how often. It’s especially normal when it comes to balancing in-law visits (whether yours or his). What isn’t normal is how long it is taking for you and your husband to come to some comfortable resolution. Clearly arguing isn’t getting you there. So stop! You won’t get a different result by going over the same ground again and again.
If the two of you could come to a comfortable compromise, you would have done so already. Please see a couples therapist. I don’t make this suggestion because I think either or you is wrong or crazy. I make it to encourage you to take a different approach to solving the problem. Often an experienced family therapist can provide a safe and neutral place to work through a problem. By adding some insights and suggestions, the therapist can help you get unstuck.
Neither of you should just suck it up and just go along to keep peace. This is important work. Figuring it out will help you strengthen yourselves as a partnership and as a parenting team.
I wish you well.