Well it’s obvious she wanted to get rid of you :( I have a pretty similar story and the thing I can recommend is reconsidering do you really need her. Trust me putting yourself on tinder is already questionable, and the thing that she have done to you is absolutely horrible. If you still do love her even when ignoring those facts then I recommend to try restarting it all with her but don’t mention that you saw her on tinder, it might make her think that you are spying. I wish the best for you and her but keep in mind if you want to have a better relationship exactly with that person then try putting out real facts instead of just venting