Sex life

When do you think it’s safe to say there’s a serious problem in your sex life? It’s really been since our daughter was born almost 2 years ago. I’m married, been married for 2 years but with him for 7 years. We have a 2 year old child. When we were just dating, we were crazy about each other. Well this was also the period when he cheated on me multiple times in the worst ways you can imagine, but also the times that we were the closest and most intimate (obviously when I didn’t know what was going on). Now we’re married and settled down and we have sex maybe once every 3 months. I’m not kidding. And it’s me that has to initiate it and really push for it. He has a horrible track record but I don’t think he would do anything bad now at this point in our lives. I don’t really check his phone anymore either though. It I just feels like we’re living two separate lives under the same roof. I have to harass him to come inside each night to spend time with his child. Forget any “us” time. It doesn’t exist. For the first time in So long our daughter fell asleep early so we got to watch a movie together. He looked miserable the whole time and when I tried to make little jokes that could lead to intimacy he said “NO I’m tired” when do you reach the point where its suspicious? Could it mean that we just have other issues? I mean we argue alot, plus our daughter still cosleeps with us so I feel like that could be a barrier but I honestly think even if she didn’t we still wouldn’t have sex. He would say he’s tired still. Does this happen when your relationship is strained or is it a telltale sign that hes cheating? Because I’ve seen other posts like couples fight so much but they still have sex at least to release some tension. My husband wants absolutely nothing to do with it and I want it a lot less than normal but I’m still always the one to ask for it. It’s just a horrible feeling to feel rejected every time, especially since it’s so rare that we actually do have sex. It makes me feel completely self conscious and horrible about myself. It brings up so much anxiety from the past. And yes I’ve told this to him and tried to talk to him about it and he pretty much says he doesn’t want it because of how much we argue. I’m just so lost and would love some advice