Wow, that is a lot to deal with. First, I'm really glad you're looking at five years without harming. That by itself takes an immense amount of courage, and I absolutely know what it's like to battle the urges almost constantly even though you haven't actually done it in years.
Second, please don't feel defective. You've been through a lot and your feelings are absolutely normal, all things considered. I know I would be right there with you in feeling badly if all of that happened to me. Scary thoughts happen, and they do not mean that you're crazy nor that there is anything deeply flawed about your personality or anything like that.
Third, I would definitely recommend seeing a doctor, and if you can, have him refer you to some sort of therapist who does "talk therapy" as opposed to prescribe meds. There's nothing wrong with medication--and who knows, you may end up finding a lot of good in it--but it sounds like you've got some problems you want to solve regarding social support, being a good parent, and having a long history of rejection from people you care about a lot. Those are very "human" concerns that can't be solved by taking a pill, so I'd see if you can find a therapist who can help guide you through it all.
Ideally your doctor would also be able to refer you to someone who can give you a psychological assessment and help you to have a little breathing room for you to get your life back together. I don't know your personal history or what you've been through, but it sounds like you've got a history of depression and panic attacks at the least. Your relationship history and self-harm history combine to sound a little bit like borderline personality disorder, to the point where I'd ask about it, but that's a question I'd bring up with your doctor if you ask for a referral. Again, I don't think you're crazy, damaged, or anything less than a good person who wants the best for herself and her son, so I hope you don't feel threatened by my mentioning these things.
Fourth and finally, there's no need to feel guilty about any of this. You're trying your absolute best and I'm proud of you, even though I don't know you. Give your son a hug for me <3