Baby blues or post partum depression?

The first week after birth I felt elated, happier than I have ever been, now I just feel... sad. Dont get me wrong, I love cuddling and loving on my baby, but I literally cannot shake this sad feeling, and this feeling of impending doom..

My husband can tell I'm off, he thinks I'm mad at him but I'm not. I told him that, but I cant seem to tell him that I'm sad, or that im feeling like something bad will happen soon, or that I feel like I'm not going to amount to much as a mother.

I've given up everything for my baby just in this last week, but I still feel like I'm not doing enough. Not cuddling enough, not feeding enough (even though its every two hours or earlier if he signals he is hungry)

I look at my baby and I just want to cry, because i dont think i deserve him and for no particular reason either. I just feel like I'm not enough for him, or my husband since my poor husband isnt getting any attention since the baby has been born. (He is fine with that though, he knows that I'm going to be more focused on the baby because the baby needs me more since he is exclusively breastfed and doesn't take bottle)

Baby was born 6lbs 8oz, and when we went to his five day old check up he was 6lbs 3oz, and the look the lady gave me made me feel like I was doing something wrong. Even though the doctor assured me he was fine as long as he was having enough wet diapers and j was feeding him every 2-3 hours, the look the nurse gave me made me feel like shit.. and maybe that's just my brain doing that.

I have barely got any sleep, and I cant seem to sleep when baby sleeps.. I just watch him, or sit beside his bassinet and watch TV while he sleeps. I had a very difficult year last year, and my doctor let me know that I may be at a higher risk of PPD but I dont think its suppose to happen that quickly?

I dont know what to do besides deal with it since my next appointment is in five weeks