I can relate to this as well. I think A LOT of women have trust issues, and I have met my fair share of men who do, too. Here is what worked for me when I was dealing with my trust issues in a relationship, and it really helped over time. If you are willing to spend the time and energy working through her problems WITH her, you can definitely make it work.

When talking on the phone, or through email, or any long-distance communication with no face-to-face interaction, it is easy for the other person to get lost in their perception of what you are saying, rather than actually hearing you. I would suggest talking to her very calmly the next time you see her. Let her know you want to sit down and have a heart to heart. She will probably like that, as most women enjoy intimacy and emotional bonding. Do not tell her you want to do this in advance, thereby giving her time to brood and come up with all sorts of stories and reasons why you would ask to have a heart to heart. Just do it the day you see each other.

Start off with the positives. You love her, you want to continue having a relationship with her, and you want to work out your feelings and be honest with her so you both will be able to enjoy each other more and get back to the good stuff. You want her to feel safe and secure in the relationship, and talking out problems will help her do that. Then gently let her know that you feel like she might be getting paranoid and insecure while the two of you are apart. Let her know that you understand where these feelings come from, and are willing to work through them with her, but that she has to acknowledge them and deal with them in order for the two of you to really move forward and have a healthy, happy relationship. If that is what she wants, she will be glad you brought it up and will be willing to work through it, so long as you refrain from sounding abrasive or blaming her for anything. The approach is that you want to work on the relationship, not fix her problems. Let her know that you might be doing things that trigger her insecurities, that it's not just her, and that you are also willing to do some work on yourself. This will make her feel less singled-out. Then just tell her what she does, and how it makes you feel. FEEL is an important word here. "When you accuse me of ___, I feel defensive and hurt. I want you to trust me, and know that I would never intentionally hurt you. How can I help you feel more safe in this relationship?" It's a start. This conversation is one that has to be had over and over again to make progress. After you have had the conversation, she will enevitable feel insecure at some point in the future while you are on the phone with her, and at that time you can gently point it out. "You are accusing me again. Why? What is really bothering you? Remember when we talked about this? Tell me what you are really thinking, or what is scaring you right now so we can work on it."

This is what worked with ME. I'm no therapist, but I personally think therapy isn't the only answer. Therapists are there to help someone work through their problems, not solve their problems for them. If you are able to sort things out without therapy, then you are saving yourself a lot of money, which is good :-) If, however, nothing seems to be working, then her issues may be too deep for you to help her with, or for her to help herself with, and therapy is definitely necessary at that time.

Those are just my thoughts. I hope they help! Good luck to you. I know that trust issues are painful for both parties involved, so I send hugs to you and your girlfriend and wish you both the best.

*hugs*