I think I have PPD

I'm ashamed to bring up to my doctor that I might have post partum depression. I'm ashamed to tell my husband I might have ppd. I'm ashamed because my son is 8 months old and I don't want them to think I'm crazy for "feeling" this way after so long. The other day I was reading an article about ppd and its symptoms and I just cried and cried. 
I quit my job a month and a half ago because I couldn't focus. I'm suppose to be job hunting but I haven't found any motivation to do so. I'm also in grad school but I've been slacking off there too. I don't even watch my son during the day because my in laws do since they do not know I quit my job. So I have plenty of time to be domestic but every day I get up and nothing gets done. I have no desire to be around friends. I have no desire to do anything at this time. But I'm ashamed and I'm scared of what my husband and doctor will think if I admit to these feelings. 
When I had my son, I was very sad and teary all of the time. The lactation nurse took notice of this and even asked me if I could be having the baby blues but I brushed it off and said it was just my hormones. I pulled myself together and told myself I am not experiencing ppd. But every now and then, I still find myself in tears. Im in tears now as I write this. I really don't know what I want out of posting this. I guess I just want to get it off my chest and see if my feelings are normal or if I really might be experiencing ppd.