Throw the fucking spice shite in the bin or better yet flush it down the toilet. Consider going to Narcotics Anonymous meetings in your local city. I'd say there would be many ex-marijuana user at NA meetings that have messed around with both normal weed and synthetic marijuana. These ex-addicts could offer you advice and support to stay off Spice long term.
Although if Narcotics Anonymous isn't for you your local doctor could recommend first some one on one counselling followed by some group drug counselling from a qualified therapist that's trained to help you stop the repeated relapses and put things in perspective enabling you to have motivation to stay off fake weed.
Then again for some marijuana users the only way to cease using the drug is to have a 2-4 week stint in a mental health hospital ward so you can fully detox from the weed and safely use a regime of benzo's like valium to deal with the withdrawal symptoms like irritability insomnia and night sweats. A stint in a mental health hospital is similar to a stint at rehab but the mental hospital would be likely at a public hospital so would be free to attendant where as a rehab clinic is usually a private run institute that typically cost thousands of dollars to attendant a 30-90 day detox program.
Worst case scenario opusxzy you could have a drug induced psychosis, that is a result of using Spice fake marijuana heavily over an extended period of time and the way to explain a drug induced psychosis is that you experience a break from reality that happens due to a nervous breakdown where you become overwhelmed with anxiety and feelings of anxiousness while developing psychotic symptoms like hearing voices and feeling like people or things are sublimely communicating with you through TV, radio internet websites. Sometime people in a psychosis stage think other people can read their thoughts. Basically full blown disturbed irrational paranoid thoughts. For a normal stable sane person these symptoms would be easily dismissed but to someone who is sick, mentally venerable these emotional symptoms and paranoid feelings would feel totally and completely real. The only proven medical way to recover from a nervous breakdown is to be admitted to a high dependence wing of a mental hospital and be given powerful anti psychotic medications and tranquillisers to bring the un-stable person back down to earth and thinking rational thoughts. Another reason for needing to put the person in high dependence medical care is a person suffering a nervous breakdown are often prone to committing or attempting suicide.
I am not saying it's a certianty you will have a nerous breakdown opusxzy but for me when i was 21 around three more months before my 22th birthday i was strung out smoking half an ounce of skunk weed in a week i actually got to the point i didn't have the self awareness to realise i was slowly but surely losing grip with reality and i needed to smoke weed to sleep, needed to smoke weed to feel happy. And out of nowhere i got sick and i can remember crawling around the floor of the flat i was living in at the time trying to stay out of the line of sight of the windows as i had the cricket on TV and i had a feeling that the cricket commentators would talking directly to me sublimely that a sniper was in a adjacent building waiting to shoot me when a Cricketer player batting on the game on TV was going to get caught out. Losing the plot was a terrifying and almost traumatic experience but it was the only way i was going to get the help i needed to stop smoking weed and detox from this so called soft drug.
Don't be alarmed opusxzy it's not a certainty you will have a full blown nervous breakdown from your Spice use but if you want my advice If you really can't stop using fake marijuana try to nip this problem in the bud and get ahead of it before it gets ahead of you. See the Doctor that is treating you and prescribing your antidepressants and xanax and try get up the courage to have a honest and frank conversation with this Doctor as i think the whole reason you can't stop using this Spice synthetic weed is you can't handle the detox and withdrawals. A short couple of weeks stint in a good public hospital mental health ward could make the world of difference.
Good luck and be well
