What is this lump in the chest

I am feeling it again - that lump in the chest that comes with the sadness. Most of the time I don't even know why I feel that way. Wait, I do know, but the rational side of me can't even justify why I should be feeling that way. This time it is because I feel that I am ignored by Dzan. Ignored is too strong a word - it should be he is not paying as much attention as I would like him to. And this is despite knowing that I am sharing him with someone else. And that he already mentioned that he can only give this much, and if I feel that it is not enough then I would have to look elsewhere. And he has a baby to boot. Am I being my Cancerian self? Again? I know I need to get this out from the system. And I know I need to look at the positives - that he loves me. That he wants to be with me. That I mean something to him. Why can't my heart just follow my head?