I have been/was in exactly the same boat with childhood abuse and trust issues, especially with the opposite sex. I would start dating people but get scared when they really started to care about me and I'd run...too scared to let the walls down and too scared to let them in and trust them.
The only helpful thing I can venture to offer is that refining your discernment of who is trustworthy is important. It's not 'trust everyone vs. trust no one'. Some people do not deserve trust, but trust is something that is definitely key in relationships and healing.
Someone once told me that how much we trust others is a reflection of whether we trust ourselves. The more inner peace you have the easier connections and interactions with others will be. It took a good year of therapy for me to get anywhere near something I would call inner peace. Good luck.