Trust is difficult. Once trust is broken, it can be nearly impossible to learn to trust again. This opens up two challenges: knowing how to deal with people who refuse to trust and knowing who it actually was who truly, really, broke trust in the first place.
On the matter of dealing with someone with trust issues, it’s best to not compound the problem. Even the smallest thing can trigger an avalanche of self-justification for why that person shouldn’t trust you. Patience is your best bet. On relearning trust, admitting the challenge and accepting friendship are the first two steps.