Relationship Anxiety

This past week I had re occurring self destructive thoughts about my current relationship and worrying about not being "in love" with my partner. I know I love them and value them but for some reason I keep getting this overwhelming anxiety followed with those thoughts. I can reason with myself and for a while and if I'm walking around or with friends I'm fine (mostly) but when I'm settled in my room or just in the dark I fall back into the depressive episode and the thoughts come back. When the anxiety subsides I can see that I do love my partner but it's just not that "honey moon phase" love. It's comfortable and normal. But I can't stop associating this anxiety with my partner! No matter how good and confident I feel I roll back into anxiety. I'm not sure if talking about it is validating the emotions or giving it power but all I know is I don't wish to lose my partner over this. I just need some advice on what to do with myself to stop associating my relationship with this sad anxiety. Or maybe an explanation? Please help!!! I don’t want to ruin a great thing because of my head..