Vent/Stoytime i guess? (I'm just gonna yap for a little)

Ok so, I found out today that my boyfriend was cheating on me with another man, I honestly don't know what to feel. It feels weird saying that I'm used to this happening but its true, I'm usually blocked or cheated on within the first month. It's normal at this point, is this how relationships are? I do know one thing though, I feel like a rabbit that's been thrown into a pack of wild dogs, it's like life doesn't actually want me to be happy yknow? I've begun to feel a little jealous towards a friend because he's in a happy relationship. But I feel guilty for feeling that way, like if I feel like that then he wont be happy. I don't know what to do anymore, I've started to give up on love honestly because it seems like I wont get any of it from anyone else. If anyone can give me any advice that would be greatly appreciated.