Well, we can't give medical advice here and we shouldn't: please contact some facility that can help you with your withdrawal, even if it simply a phone call to an ER.
You might be past the worst of it, but I am cruising a little too close to giving you medical advice here, so please make some calls.
I would also suggest making a call to AA or another recovery hotline. Your instinct may be to weather this out alone, but it can make an enormous difference if you reach out to others at this time.
You are not alone. There are frequently dozens of people online on SR at any time. And, yes, we all know how it feels to be scared when we quit.
And, welcome to SR!!!!
Keep coming back!