Diagnosis Man-baby
I understand why you don't trust easily. She broke you, she left you, she crumbled your fragile heart and now you keep it hidden from the world. After 18 months of being friends I'm starting to wonder if you'll ever open up completely at all? Are you that damaged that you can't let anyone in? If so, I'm not your girl. So go now, before my heart gets more attached.
Occasionally you show your empathy, your deep emotion. Your compassion for others and ability to drop what you're doing to help shines bright. But it's all on the surface. If there is a question too personal, you back down. You shut down and run away. Conflict isn't your friend, and compromises aren't easily obtainable.
I'm many things, but a therapist isn't on the list of things I am... especially when I don't see a happy end game. So here's to you working your shit out on your own, because from now on my counseling and advising services are closed. Please tell your new life advisor about your issues up front, so they don't get overly invested like I did. You disguise that shit well, but when it comes out it's like a festering wound.
Your diagnosis for the time being is Man-baby with bruised ego and inability to express true feelings. I don't mind meaningless sex, but I do mind it with my best friend. So I'm out. (That includes the sex, too).