It is unfair to your current gf because if the ex comes looking for you, wants you back, you will break up with gf and go back to ex immediately.

Set your gf free so she can find another man who will love only her. You love her but it seems you’re not “in love” with her enough to rid of your feelings for your ex. It is obvious you’re not over your ex, not by a long shot.

Wish you peace and am happy that you have been honest with her. Some men wouldn’t feel bad or guilty.

I do agree being on your own might help you see that there are reasons why you and your ex are not together and it’s been nearly 2 years and she is not back in your life so that does say something, doesn’t it? Has she made any contact in this 1 1/2 years? if no, then chances are she’s moved on. Was she divorcing as you two just got together or were you two involved while she was still married?