I’m not too sure what to do

So I have been talking to this guy on and off for almost a year now and I feel like i would like to be in a serious relationship with him. But I felt like being single was best because I’m scared of getting my feelings hurt, to look dumb, and for him to do things behind my back. (Im not saying he’s done that but all my friends and the people around me look dumb since they are in toxic / unhealthy relationships). I’m just afraid to be in another relationship that’s toxic when I’ve already been in 3 that were already.