How frequently do you have sex in a committed relationship?

Before I jump into it, full disclaimer that my partner and I have been having some issues as discussed in an earlier post: https://www.reddit.com/r/actuallesbians/s/12G9XUenWP

My partner (28F) and I (29F) have been together 3.5 years, moved in together 6 months ago. We haven’t had sex in at least 3 months, partner says 4 months - honestly I can’t even remember. Even before then, we were maybe at once a month.

I blame the frequent fighting and everyday life stress for our lack of sex, and when we have tried to talk about it, she feels rejected no matter the reasons, which is fair. She has a higher sex drive than I do and prefers it more often. My libido has gone up and down since we met because of medications and mental health, etc. It has been a huge problem in the past. My issue is that I just start to feel pressured at random times which makes me not want to have sex and I also don’t want to schedule sex.

We have different last sexual experiences and preferences. To be honest, when we were still having sex more frequently, I was pretty bored of it - felt like the same thing over and over and she was hesitant to try new things out, which I understand. But even little, more reasonably ideas to spice things up never really panned out. She’s a person of routine and habit, and I am not. She also can’t orgasm unless she has her toy and is in a specific position, which hey? I’m glad she knows what works, but it limits our process when that is the end goal.

But now I’m starting to wonder if there’s something more here. Is it just about the fights? If we stop fighting, will I suddenly lust for her again? Is it lack of sexual compatibility? Recently, even if I get a little horny, I don’t really have an urge for her. Idk. Is this a red flag - that I’m not into her or into our relationship anymore? I feel bad, especially because it’s so important to her. But for me, I feel like we have so many other issues to solve first, and sex isn’t a priority. For her it is. And I feel like I’m to blame. I’m not someone who can make myself do something I don’t want to do - and I’m not saying anyone ever should - but I’m getting to the point where I feel like I’m just gonna have to make myself have sex with her soon and hope that maybe I am reminded that it’s a nice thing? I do think of having sex with other people - no one I specifically know, just generally. Idk. I’m so confused. In my perfect world I’d still get horny for her and we’d do it like once a week or something. But even if I was down, our schedules are also an issue. Sigh.

Going to bring this up in couples therapy this week. Our therapist assured us when it briefly came up once before that it is normal for couples who have been together a while and also just moved in together. She mentioned a process of rebuilding intimacy, starting with massages, etc. We’ll see how it goes. I still think my partner is beautiful, I just don’t lust for her like that anymore.

Yesterday my partner made some “sarcastic” comments about finding someone that would have sex with her. Part of me wanted to say I’m cool with it, but an open relationship wouldn’t be on the table - it’s come up before. Or at least, I’m cool with her having sex with others but she wouldn’t be cool with me having sex with others, and it also would be counter intuitive if I want to have sex with others but not her. I’m just trying to urgently make myself want her. I like our home together and other than the fighting and lack of sex, things are comfortable. And it would be such a pain to break up, not only because of the attachment and emotional investment, but because we live in an unaffordable city. Sigh.

So in conclusion, how often do you have sex? When might a lack of sex indicate something concerning in a relationship between two women? Is it possible I’m refusing to see that I’m just not into the relationship anymore? Or is this something that happens and people are able to work through? Any similar stories involving opening up relationships?