How to tell the difference between being in love with them and being in love with the idea of them?

I've (26F) recently been going through a break up/make up cycle with an FA (28M) after having a wonderful year with him and I'm having a hard time trusting my feelings about him, especially now that I'm aware of the things that I do and why I do them. I find myself asking the same question each time after they've ended the relationship and I'm distraught as usual, which is: Do I really love them, or do I just love the idea of them? I usually use time as a huge indicator of my feelings about them (like if I was with them for a yr, then it was actually love, if it was a few months, then it was the idea of them), but I'm not sure that's really a good measure to use.

Does anyone else ask themselves this question? And if so, how are you able to tell the difference? What does love actually feel like?

ETA: I realized this can be confusing, my ex and I have only broken up once, this past December, and started talking about getting back together 2 weeks later. I have these thoughts after every breakup I experience, when the anxiety starts to kick in.