TW period talk, female anatomy

I need advice, I have started a relationship with someone who's poly about a year ago and we have been getting more serious for about 6 months. He's 9 years older and knows more about poly relationships than me so a lot of what I know I learned from him, I also researched things on my own and I'm figuring things out, making mistakes and it's a complicated process. One thing I struggle with is getting heard and being assertive, because he has a much bigger personality than mine but both of us are working on it and I really love him.

It's important to mention that my partner is going through a very stressful situation with his daughter and it might affect his actions.

I have an IUD for managing my endometriosis symptoms but it's in its last year of life and not working as well so I've had spotting and a light to very light period for now two weeks. I've opened up about how scared I was that it would mean he would go sleep with someone else as soon as I left his place, because it would make me feel like he's just waiting for me to leave to... get it out of his system. Which I'm not saying it's a bad thing, I could be ok with it if hes honest about it before the fact, I'm not even a 100% sure why I feel this way, I guess the fact that I was almost symptoms free for 3 years and having them come back all of a sudden really terrified me.

I'm not closed to him seeing someone right after, I don't really subscribe to the idea of a certain number of hours or days in between partners normally, just do what's right for you, but right now I'm feeling like I cant provide something and it's a scary place to be, I'd just want to have a conversation first at least. But maybe that's not how it's supposed to work and I might have ridiculous expectations? I was very vulnerable and honest with him about this and he reassured me that it wouldn't happen this specific day, at least that's what I understood but now I'm questioning myself because I don't think he understood the same thing? I thought our conversation was clear but maybe not.

He doesn't like to have any intercourse while I'm on my period which I get, not everyone is comfortable with that, but he mentioned that he was considering opening up a bit more and do it in the shower for example (which didn't end up happening). He also made a joke when I offered him a blowjob about his hand being more efficient and he felt like he was taking advantage of me if he got a blowjob and I got nothing. Now I know his "hand" joke was just a joke because he's often asked for blowjobs and we have amazing sex, but it's like he's not interested unless he can also get penetrative sex.

And tbh, that joke really hurt my feelings, again, I don't know if it's me being too sensitive perhaps?

Yesterday I know his other partner texted him because I saw the notification when he was showing me a video on his phone and when I went somewhere else for a few minutes, I know they had a conversation which I didn't even register in my mind really because that's nothing out of the ordinary but now I'm not sure...Then later on he mentioned wanting to have a day to clean up his house and work on a few specific projects so he dropped me off, which I was more than ok with.

We ended up having a nice conversation online with other friends late last night when we were both in our respective homes and during this time he mentioned that his other partner called earlier to see him but he said no because he was busy (just as he told me) and he was enjoying his time online.

During the conversation people were talking about oral sex and I said I wasn't that comfortable receiving it and right away he asked: Why? Is it because your vagina is shaped so differently? And he tried to backtrack it saying he ment people in general and not me, but come on, Im not that gullible, I have an innie vagina I guess that's what he meant, it is a bit different but all of them are unique to me, so I don't get why he would say that, and now I can't get this comment out of my head. (New complex about my body unlocked, yay me!)

Now this morning I texted him a sweet good morning text and got a one word, kind of rude? reply (Hard to tell tone from texting so I didn't mention it to him as I didn't want to add to his stress and I could be wrong) I also asked if he wanted to have a chat and he never replied which is out of character for him as he's not working today but I know he saw my message, after 4-5 hours without a reply I called and he answered and that is when he told me he went to see her last night during the night.

I want to be transparent here, I do have another partner I live with who I have been with many years, but it's not a good relationship, we hardly ever have sex and are more like roommates/good friends at this point, but real estate being what it is I can't move out yet, I want to make sure I mention this because Im not sure I have a right to have any opinions on my partner seeing anyone else if I live with someone else?

I'm hurt but I don't know if it's justified ? Part of me thinks maybe I should not be in any relationship at all with anyone right now if I can't not be jealous and I can't even provide sex for him/them? Is it jealousy or something else I'm feeling? Did he lie or just misunderstood? I try to understand and be mindful of his needs too because he really his going through a lot, but I don't know what to think anymore.