You can't get help if you don't trust people enough to open up. I know that's scary but you have to do it. If the meds you take don't work, a psychiatrist can prescribe different/stronger ones. This is what I have and it works to stop things when my brain is doing this, giving me back my functioning ability.
You don't need to tell your parents anything about this. Your health is your business so don't worry about their opinions because they don't need to know.
Nobody is going to take you child away because you feel like this, but even if they did it still wouldn't be your fault. Firstly because you're ill and you didn't make yourself ill, it's not your fault. Secondly because your son has a father who isn't ill. If your son was taken away it would be his father's fault, not yours. If your son was taken away it would only be because you were in a psychiatric unit and he couldn't be there with you, not because you're a bad parent, so he'd be returned to you when you were discharged. But you're not nearly bad enough to be hospitalised, so all this is irrelevant. Although for the record, hospital isn't so awful. It's not fun, but it's not awful.
You parents are unsupportive, so if they disowned you you won't have actually lost anything worth having, just a pair of judgemental and unhelpful people who caused childhood anxiety and contributed to your current problems by doing so.
Your partner is unsupportive and needs to understand mental illness is illness. TBH if he refuses to acknowledge that he's not worth having either. The last thing you need when you're unwell is someone blaming you for it. There's nothing for him to be embarrassed about, it's a ridiculous response to someone who is ill. He should be caring about your health, not worrying about how it looks to others if his family unit is less than perfect and contains an ill person. Would he be happy if you ditched him if he became ill?! No, he'd expect you to stand by him and be supportive. So fuck him and his embarrassment. You don't have to manage his emotions for him anyway, let him feel however he feels. Especially at the moment, you've got enough of your own feelings to be dealing with.
Why do you think your partner won't cope with your son? He's a grown adult and he's a parent, I'm certain he'll manage and it's time for him to step up whether you're at home or in hospital. If he's unsure about something he can ask friends or relatives for advice or sign up for Mumsnet.
Everyone pressurising you to do everything and be everything they want you to be is likely contributing to wards your anxiety getting worse. They all need to back off with that pressure and step up to do whatever is necessary, whilst you take some space to recover.
Learn to start putting yourself first. That's how you can be the best parent. That includes asking for help when you need it and trusting the mental health professionals.