I might be bisexual

So I'm 18 I've dated guys my whole life recently I had been dating a girl for about 7 months and we had our ups and downs and our relationship was a secret until I was ready to come out to my family well now I've let her down countless times in order to keep our relationship it's been about 2 weeks since we broke up and I'm not sure it was for the best I want to be with her. I'm pretty sure she hates me and I think she still loves me but I don't know how to get back on her good side I don't want to hurt her anymore. I started talking to another guy but I just don't get the same feelings I do as I did when I was with her. My heart really hurts and I don't know what to do