Gaining a cancers trust?

Ok so what is the best way to gain back the trust of a cancer when they have retreated back into their shell?

the reason why i broke up with her wasnt stupid. we were having problems and then she was distancing herself. but i havent been with her now for two months. you know after the break up i wanted her back, tried and failed. so i moved on. however, now that its been longer, i like being single, but i do miss her and I feel like i should at least maybe give it another try. but the issue is gaining back her trust.

Moon eyes said all I wanted to.