Hi mcviking,
You sound like your overwhelming yourself with fear. Ive been in jail 4 times..2 duis,2 drunk in publics, and got beat up by a cop. Ive learned you got to tackle one problem at a time. Number 1... Stay clean and sober. All your other worriers will work themselves out and you will be fine. Try to live more in the moment rather than worring about the future or regreting the past. I know its easy to say but if you really do it you will see a drastic change. You will probably get 3 yrs probation and have to pay a lot in fines and do drug class for 6 months.....just make sure you do everything and get pass this. These are misderminors not felonies...employeers dont really look at these. Just stop now because things will only progress more if you dont stop....if your in an accident loaded then you are really screwed....that is a felony.
Good luck to you