You are not required by halacha to reveal your “issues” up until wedding plans are underway. The smart thing to do is not reveal these things until you’re both ready to get engaged. Of course the possibility of breaking up at that point is all the more heartbreaking and painful, but it’s the logical thing to do if it’s preventing you from getting married. I’d say at least 50% of women would not break it up at such a late stage into the relationship. What matters is how you explain it to her. Rehearse with a friend, talk to your Rebbe.
This may not be in accordance with halacha. Check with your rav. -29