I haven't had any other addictions, but as hard as it's been to quit nicotine I can't imagine anything being any harder.
I chewed tobacco for almost 25 years, quitting 2.5 weeks ago! As you can see I'm right in the middle of the battle! I "quit" many, many times but none of those quits took. I finally got to the point, mentally, where I was talking to myself about quitting, I knew I had to do it but I dreaded actually doing it. I had a couple of co-workers at the FD go on this Chantix stuff and it worked for them! I have been on it for the last 3.5 weeks (you get to continue chewing/smoking for the first week while you're taking the medicine) and except for a couple of fleeting, late night, post-meal urges, I've been clean. It's not over by far but as of right now I'm feeling pretty good. This whole thing has become a freedom thing for me. I used to always have to know where my can was, if I was leaving the house it was always on my mental checklist, do I have enough to last through whatever I'm going to do? It was exhausting. I used to buy a can per day and on doing the math, like many others who have commented, I couldn't believe how much money I was spending on the stuff, ridiculous!
If you can, try Chantix, I think, depending on your dept./health ins., you might be able to get it for the cost of your prescription co-pay. If you have to buy it outright, it's expensive, but you'll still be money ahead.