You cheated, you lied and even though she claims to have forgiven you, your girlfriend can't seem to forget the past. When her trust is broken, building it back up is a must if you want to continue your relationship. You need to tune your actions and words into her needs, proving that the past is gone and you're a trustworthy person.

Time Table

Even though your girl says that all is forgiven, don't expect that her trust will magically reappear overnight. It takes time to prove that you're trustworthy. Instead of saying "trust me" over and over again, show her with your actions. For example, if you say that you're going to the library to study, go to the library and don't go out with your friends instead. The more that your actions show that you're being open and honest with her, the more likely it is that your girlfriend will eventually trust you again.

Apologize Sincerely

Apologies show that you understand you've done something wrong and that you care enough about your girl to make things right with her. The key to a successful apology isn't simply to say, "I'm sorry," it's to truly understand how your offense hurt her. Get specific and apologize for the exact offense. For example, if your girlfriend can't trust you because she caught you texting your ex, say something such as, "I'm sorry that I lied to you and kept in contact with my ex-girlfriend. I know that my actions hurt you, and I was wrong."

Positive Past

Instead of just focusing on the negative aspects of your past, remind your girlfriend about what first attracted you to each other, suggests clinical psychologist Lisa Firestone in "5 Things to Try Before You Give Up on Your Relationship," for Psychology Today. For example, if she keeps bringing up the time you lied about losing your job, reminisce about that special spark that you felt on your first few dates or reflect on the months -- or years -- of positive memories and moments that the two of you have shared.

Focus on the Future

If reliving your happiest past memories isn't doing the trick, try focusing on the future. Make a pact to look forward, and not back. When she brings up your past offenses, turn the conversation around and talk about where your relationship is going. Talk in specifics, noting what you both want from the future or activities that you are planning. For example, talk about how excited you are to have some alone time with just her on your upcoming weekend camping trip.