Langdon, you need to follow your heart AND your head. Since you are just tentatively getting back in touch now, your fear is very understandable. Let him know you are very glad to hear from him and you miss him. But it probably wouldn't be good to go over-board and say everything you've been saving up to say for the last three months, right?
Realize that the road will be very rocky and that your emotional strength will be tested. You have to learn to set boundaries, or, as Anthony said, don't be a doormat. Every relationship requires boundaries, but that is especially true with PTSD. It may also be that you will be shut out again at some point in the future. You have to decide whether this relationship means enough to you to cope with that. Your decision regarding what your heart can take will guide you.
Cowgirl