I always feel bored after entering relationships…

I have absolutely no idea why I always feel like this a few weeks/a few months after entering relationships. It’s been a main issue with my 3 recent relationships, 2 being ex’s and 1 being the relationship I am currently in. I first noticed this with, lets call him ex no. 1, after about 3 weeks into my relationship with him I decided I was bored and have the same feelings as I am having now. I was constantly thinking about breaking up with him, thinking about whether or not I should talk about it with him, or if I should just ignore it. I feel part of it is because my relationship with ex no.1 was long distance and I had never met him so it made me bored easily i guess. About the same time I started feeling these feelings, I met ex no.2, we talked for a while and about 1-2 weeks later I broke up with ex1 and started dating ex2. The same thing happened around the same time frame as my previous relationship, about 3 weeks into the relationship. I was confused with this as my previous thoughts were oh maybe its just because I am not able to see him in person yet but it wasn’t so it made having these feelings worse for me. I still continued with that relationship for 7 months while still having these feelings. Theres been times when I almost broke up with him but then wouldnt because I would feel guilty. I did actually end up asking to at least take a break but then instantly was like nevermind and we stayed together. We had ended because I found out that he had lied to me about some things and had cheated but I still had felt guilty, like I was doing something wrong. That’s another thing is that I feel guilty if I do it. Now into my recent relationship. We’ve been together since August 7th so like 2 almost 3 months now and I am recently started to have these feelings again. It’s eating me up because this guy I am with now, I truly have great feelings for, I just am bored. I dont understand what causes me to feel like this and I hate it. I long for a relationship and as soon as I find one that I wanna be in, I just can’t.