You're hesitant because of past experiences that you have had which leave you with a sense of vulnerability.

If you were, hypothetically, to get into a relationship, don't jump into it all gung-ho with an all or nothing approach.

Step back and take it easy, one step at a time.

You may want to consider telling this person that you're working on some issues right now and you are positive that you are going to make progress, without having to disclose a diagnosis from the get go. If the relationship does start developing into something a bit more serious, you may not be able to hide this very well. But by giving soft hints at first, the message might be received more readily later on.

Just a thought.