This is the only solution if the thought of your ex and the new guy is not getting out of your head. A week after this, I found out she had already met someone else and is moving on. Again, I made a massive mistake by losing my shit when I found out about her being with someone - mainly because she had continued to string me along with hope until the day I heard about the new person, and it really really hurt. I have done a lot of improvements in myself and on the reasons which caused the break-up. The best and most attractive thing you can offer her right now is your strength and independence from her situation.
But this is just speculating as I have no hard evidence.
In love with best friend but she just started dating someone else. Any advice?
I think it would be okay to remain on talking to terms, as you want to be certain she still has feelings for you and would be willing to leave her current relationship to be with you, or you would end up breaking up with your current girlfriend just to end up getting hurt. Unfortunately, only she can make that decision on her own to realize her mistakes of letting you go. So do I before this stuff happened we were helping each other out with it when she she was in Texas.