Just take sex off the table for a while. If you go out, remove all expectations for how the night should end. Enjoy the conversation, the companionship, the time together. It may also be best to go out with groups of friends, rather than one on one with a guy. You just need a little time to get comfortable in your own skin and acclimate to the new situation. If after a long period of trying this out you still have trouble moving on it might be good to talk to someone, but that likely won't be necessary. Just take some time and it will be all right.
Keep your chin up. I sincerely wish the best for you.