I agree with Leed in that more information may be required about what happened for good advice to be given. I am someone who is in a relationship where I have a lack of trust in my boyfriend because of things he has done, so out of experience I must tell you that as Leed said trust can be very hard to build back up, although it is good that you are willing to try. Just be aware it will likely take a long time for there to be trust again, and it is very hard to do.