I (M 27) am struggling to cope with my jealousy and anxiety in my poly relationship and am afraid, I wont get it under control.

For the last 1,5 years I'm in an LDR with my partner (F 36). She introduced my to poly. She has a wife and kids in a town 600 Miles away. Our relationship is great, we love each other and had very few problems (mostly about the distance).

A few months ago she met another guy from my town at an event we visited together. They grew an interest and started dating. Since then I'm a nerve wrack. It got slightly better over time, but every few days I fall down in a dark rabbit-hole full of anxiety.

I'm not entirely sure, why this guy is suddenly a problem for me. My guess is, because the relationship between my partners wife and her is mostly platonic and because he's another male. I know this feeling is dumb and rooted in sexism, but I still feel it. In hindsight, I honestly think I saw our relationship as "quasi-monogamous" because the poly aspect never came up in reality before.

Now suddenly I have problems, where I before never had them. If she dosn't answer my texts for a while, I think it must be, because she rather texts him. It brings out the worst in me. I start to become controlling, try to steal glimpses on her mobile when she is with me, to see if/what they are texting etc.

We speak open about my feelings. She is great. I love her. And I want to do whatever is possible, to keep what we are having. Rational I think I'm fine with the constellation, as long as we dont see each other less than before (about 1 time a month). But at times I cant control my emotions. And I don't know, if it gets better over time or if I'm just not poly compatible.

I lurked a lot in this sub, to get other perspectives. So I wanted to ask you people with more experience:

(How long) did/do you needed to cope, with these feelings, when you started polyamory?

In your experience, can these feelings get better, or do they show I'm just not compatible in a poly relationship ?

Do you have any tips how to cope with the feelings? My problem are not their date nights necessarily, so I hardly can plan for it.

Is it a fair boundary, that I would end the relationship, if we would see each other less than before?

Thank you all!