She brought a vibrator, I listened and now I don't have confidence or want with her anymore?

Whenever I have with my girlfriend everything was fine, she got hers and then I got mine. We each tried out new things the other wanted to do.. One time my girlfriend wanted to try out a vibrator. I'm old fashioned and don't like outside things in . But I did it anyway because I wasn't going to deny my girlfriend her "turn". So we had and she told me to use it on her...I did and I watched her and then since that night, I haven't been able to have with her. I feel really inadequate and just don't want any toys ever near us. They make me feel like crap. I feel replaced. I haven't had with her for 2 weeks so far. I just can't do it because my confidence is at zero in my sexual ability and I don't want to have sex with anything other than my girlfriend included ( no goddamn toys). I mean I gave my girlfriend her turn to experiment, but it made me feel like crap. I just know I am never going to endure using these toys so I'm done. Intimacy with my girlfriend is non-existant now because I feel replaced... and certainly don't see the toy as a "friend". She approaches me for sex ( including the toy and not) and I jusy can't do it. I decline. I feel like crap and feel that if my girlfriend prefers it to me, then I should just go and find a girl who finds them horrifying ( that is if one exists) -_-. What do I do? I don't feel masculine enough in the relationship to stay, I'm not having sex if toys are in the equation so what can I do?