Tips to have sex more regularly?

My husband and I have been together 4 years, married 2. When we met, we had sex every day, multiple times a day...this continued for the 1st year or so and has never been the same since. I have tried to ask him about it and get to the bottom of it and/or even improve anything but nothing is working. Now all we do is fight, every other day. Is this normal? I don't even know anymore.... We don't have sex more than 8-10 times a month and I feel like that's "not normal".

Any advice or tips please?