first of all, kudos to you for having the courage to post here. it took me a long time to do that.
second of all, it seems that you're pretty in tune with yourself and know that something isn't right. the best thing for you right now would be to find someone--a friend, family member, therapist, midwife, doctor, support group--who takes your concerns seriously. yes, having a new baby is tough, but the things you're describing sound more serious than just normal new baby stuff.
it looks like you're on long island...i don't know how easy it is to get into nyc for you, but there is an excellent support group in manhattan. pm me for details. the therapist who runs it is so respectful and has a ton of experience in helping women through ppd...no matter how severe. it was really helpful when i was really struggling.
also, check out
www.postpartumny.org and post partum support international's sites. and make an appointment with your ob/midwife, if you don't already have one coming up. make your concerns really clear and if they don't take you seriously, find someone who will.
take care of yourself!