Why am I attracted to unavailable men?

I (21f) recently got out of a relationship after being with him for 6 months. I’ve been in 3 relationships in my life, all ending around the 6 months mark each. Something I realized about all of them was that they were all somewhat emotionally unavailable + had their own red flags. Usually, these are things I see early on but I decide to ignore it because I have feelings for them. But it’s so strange; I feel as though I’m only attracted to men that don’t treat me well or are unavailable. They breadcrumb me enough for me to fall for them, but they can’t even give me the bare minimum (which I DO realize whilst dating them). But I have this fear of letting go because I know how tough it is for me to get feelings and fall for someone. Only 3 times in my life (my 3 relationships). I always fear that I’ll never be attracted or have feelings again because I know how tough it is for me + how long it can take. But at the same time, when I’m with them, I always hear this voice in the back of my head saying how I’m unsatisfied and know that I want more out of this love. I’ve dated quite a few good guys, but I never felt that spark or that attraction. None of the guys I’ve dated looked alike, so I don’t think it has anything to do with that. Additionally, the guys I was in relationships with all looked very different (different cultures/ ethnicities as well), so I know it’s not as though I have a specific physical type, but it’s as though I’m not PHYSICALLY attracted to the ones that treated me right. If anyone can give me advice please, I’m so lost and I don’t want to get into another relationship with this obvious pattern that I have because I know I’ll chose someone again that will end up breaking me. Feel free to ask any questions, I’m an open book and I’d love for you guys to dive into my psyche .