I'm sure you can leave the house in order to go to the doctor.
I can't leave the house by doctors orders
Just a suggestion but could you try going along to some of these places with your husband? Ask him to take you along with him. That way you're getting out more but have him there to support you and help look after your son together. Or does he have any family member that you get on particularly well with? Maybe you could invite them around and go out and see them with your son.
I'd still do what Annie Brook has suggested and go and see your doctor. You won't get help if you don't ask for it.
Good luck
Honey, it sounds like you have depression, I think there is such a thing as "prenatal depression" but with you having another child so young it could even be postnatal depression. I think you should talk this over with your doctor and see if there is anything he can prescribe that would help, or if there is a counselor on his staff you can talk to. You don't sound like you have it that bad, but you sound like you are feeling really bad, and that is what makes me think it's depression. I don't mean this to sound like I'm saying "it's all in your head" because depression is a real medical condition, taken seriously by medical people. They won't blow you off. Go see your doc. Good luck!