<human>: Can you succinctly summarize the text in 1-3 sentences?

I 26m have been with my gf 27f for about a year now. I don't think I can trust her. When we first started dating, she said she was on BC but then told me that her body works like BC and she doesn't need BC due to a medical condition. I asked her to get on it and she did. I've noticed, however, she's not great at taking it every day. I feel like I can't trust her to take it.
Fast forward to last weekend. I go out of town and she goes out with her roommate. She ends up doing cocaine, but neglects to tell me this when she recaps her weekend. I wouldn't normally care, but she went about 6 months with almost daily use a couple of years ago, but tapered off significantly about a year before we met. She'd still do it on occasion, but nothing like day long benders or anything. I expressed my concern for her because I knew her past and she immediately promised me she'd stop doing it again and it wasn't worth it and it's not fun anymore..the whole 9. I tell her that's a bit much to promise something like that, but she insists.
I found out this information because I went through her phone. I had a feeling she wasn't being honest and used that as justification to go through her phone. I found exactly what I expected by reading texts between her and her roommate. It was even more weird because the guy she got the cocaine from was calling her babe, and I think even said goodnight love the night after they met up.
I don't know what to do. I showed a complete lack of trust by going through her phone, but she also lied about what she's been up to. I don't trust that that was the first time she's done it since promising me she wouldn't due to what she said in the texts. I took pictures of the texts that prove her guilt, but also prove mine.
Any advice would be great.
<bot>: went through gf's phone, found she lied to me, but I'm also guilty of going through her phone.