http://www.medhelp.org/posts/Addiction-Substance-Abuse/Opiate-withdrawal-and-switching-addictions/show/1459613 An interesting read for you concerning withdrawal and cross addiction.
Hey, forgive me if this is long. A year ago I couldn't formulate two thoughts together much less babble as much as I do these days. Since being drug and alcohol free, I haven't been able to shut the brain off and am constantly thinking. I read your post a couple of times and thought some before posting.
How long has it been since you have used? I can only assume you're in the early stages by the symptoms you've described. Are you just taking what your shrink prescribed? Anti-depressants will not be benificial if your currently using. Time and patience play a key role when dealing with withdrawals because they consume your every thought and feel endless. The symptoms you described are classic. They should subside soon, but recurr each and every relapse ( as I'm sure you know. we all have done it).
During my addiction ( heavy opiate use as well as benzos, and amphetimines. I also drank alcohol nearly every day for 16 years) I spent many sessions with many different psychiatrist who analyzed me till I was blue in the face. All I wanted was to be fixed by any means possible ( preferably medications and I must say I did many times try to score benzos to no avail sick addict lol ). I realized sobriety was my responsibility. There's not a pill out there that would have helped had I not wanted it. I am 100% for seeking therapy so don't jump to conclusions on my next statement as it's just my opinion and what I experienced. I have been told by many professionals as to why I drank and used. Most of it centered around physical abuse as a child, experiences overseas- Samolia, Kuwait, Iraq- or just using to forget past experiences and mistakes. Some of it may likely be true. I used cause I wanted to get high.
Addicts are intelligent people I tell you. Think of the drive and determination it takes to seek out drugs day after day. Think of the stories we tell others. We could use and manipulate anyone. There were many times when I went to different doctors that if a camera were present, they would've awarded me an oscar! Use that same concept when seeking sobriety and noone or nothing will stop you!
I don't know if you will ever determine if depression was present prior to using or not. I know alot of us have it after stopping for some time. I guess time will tell. I was prescribed just about every one there is. It wasn't till I got some clean time in that the depression went away. Today, I'm fine. Sleepless nights are plentiful early on. Just try and be careful. Addiction to sleep meds is common. Good luck and sorry for the long post!