Used mothers vibrator - I'm a guy

I'm 17 years old and straight and I read about prostate milking and how it has positive effects in terms of health. I tried using my finger with a latex glove and had no luck and then I remembered i found a vibrator in my mothers room, so without really thinking about it, I took it, put it in a latex glove and tried it for about 15 seconds and cleaned it and it put it back. This didn't work but the issue is since I've done it I've been guilt ridden and depressed and can't get this off my mind. I nearly told my girlfriend (over text, she's working away at the moment) to see if talking about it would help but decided not to in the last minute after telling her I've been feeling "crap" the last few days. We find that we can talk about literally anything but I'm not sure about this. I'm very regretful and I cannot get this out of my head 5 days later. I talked to her about the prostate milking etc and she said that she thinks it's okay but the fact I used what I did is what concerns me. Should I tell her? Or should I wait to see if this guilt wears off and never speak of it?
Any advice would be appreciated
Thank you.