Congrats on 16 days! That is something to be proud of.
You have to give it lots of time. As addicts, we're usually control freaks (and like Serenity Queen told me, we're about the instant gratification and we want everything RIGHT NOW). However, we cannot control other people, if you've tried to get clean before, and didn't make it, OR people have seen others try to quit and not make it, then they are going to think you're in a phase and that you will go back to your old ways. A lot of people will think that way and we can do nothing to change or control that, except to give them time, stay clean, work a program of recovery, and prove them wrong.
It's been nearly a year, for me, and my second husband (who is in a whole other world in his head with many many problems of his own, but yet finds it easy to judge others) still thinks I am either still using and hiding it well or will go back to using. My own boyfriend worries that I'll relapse and steal his things. Does it make me angry? Yes. It does. It does because my second husband took the law into his own hands and restricts my time with our son (and I have no means to take him to court, no money, as much as I'd love to and have gotten free legal advice that the law is on my side) and I want my boyfriend to understand I can never promise not to smoke crack again, but I am giving it 100% every day, not to. But the truth is in the pudding. Time will tell and the longer you stay clean, the more they are proven wrong OR their worries are put at ease, just a little at a time.
It's never easy. It can be a very lonely time. All I can say is to dump ANY friends whom you used with or whom DO NOT CARE that you used. Keep the ones that actually care about you. Especially your one friend. Maybe invite him to a cup of coffee, when you have 90 days or so. Maybe invite him to some meetings. And keep showing him you intend to make the change and keep working on it. Make new friends. Clean friends. People who don't do drugs or drink to excess.
My boyfriend does drink. But not to excess. He'll have a couple beers with dinner, once or twice a week. And I am fine with this. It does not bother me because alcohol is not my thing. Now if he lit up a crack stem, we might have a fight over that... LOL
Anyway, relax, it's perfectly normal for people to be wary and doubtful. Stay focused on yourself. THAT will still have them wondering, until they see you are chasing your recovery, now, rather than your DOC. But keeping focused on them will only harm your recovery. Time and proof will tell whom your real friends are, and if, in the end, you don't think you have enough, go make new ones! :ghug3