Dear PTSD,
I apologize for being so long in responding back to your question. Your question really requires the expertise of a therapist skilled in sexual issues. I would encourage you to seek out someone who is competent in that area. However, I would give you these surface suggestions. Some of the sexual dysfunction that you are experiencing may simply be the consequence of growing older. You should go to a Dr. and have a complete physical. Your difficulties may also be psychological, as you suspect, at which point you need to speak to a specialist.
Whatever relationship you are involved in, communication is always the key. It is important that you are open and honest. This does not mean that you reveal everything about yourself upfront. Good relationships develop slowly over time, with discretion regarding what is revealed and when.