Postpartum Depression?

My LO is 4 months old. He is the most amazing yet challenging baby I have ever met. It took me a good month to really bond with him and I am not sure why. I was so excited to have a baby. The first few weeks after birth I felt numb. After that, the colic set in and I became super stressed and exhausted of course. I didn't really feel love for my LO until he smiled at me for the first time. I EXPLODED with emotion. I was so happy and proud that my husband and I created such a beautiful thing. I went the opposite. My LO has been going through colic, a milk protein allergy and really bad reflux. For the past few months I feel super protective over him. I don't want anyone to touch him, feed him, change him or hold him except my husband (sometimes). But if my LO starts to have a colic episode and my husband tries to calm him I ball my eyes out because it's not me doing it. I feel the need to control everything in terms of my LO. It has caused issues with my husband and I because I feel the need to critic everything he does with my LO that I dont agree with and I know I should let him do things his way but I just can't let go. Is this normal(ish) feelings or is it postpartum depression? I don't have feelings of hopelessness just anxiety and strong worry and need to protect my LO from everyone and everything.