Welcome to the site! Your name really says it all: get busy livin'. Congratulations on four days. It's a good thing you didn't have any serious complications from your withdrawal.
I"m on day 8 now and tho the worst of the withdrawal is over, I'm having some problems with memory and coordination and such things. Stress is hard to deal with too. I'm finding AA to be a wonderful help for the stress and a great place to get support. I've found a whole new family who loved me as soon as I walked into the room. If you haven't considered AA I would suggest that you try it. And if you don't like the meeting you go to, go to a different one.
Just remember your sobriety comes first. As to your best friend, yes, I would tell him you've quit drinking and if he's truly your best friend he will understand and not pressure you about it. In social situations, just say "no thanks". And if that doesn't do it, if anyone gives you a hard time about it then they aren't really your friend... or maybe are too drunk to be polite.
All the best to you!:ghug2