I just recently kicked oxys in the past two months. I was doing them pretty heavily for a year, almost always IVed and anywhere from 3-10 30's per day with very few days of less or nothing. I almost never got sick (until I quit, duh) because I almost never didn't have them.
When I kicked, however, I had two 10 mg methadone and an 8 mg suboxone to help me through. That's it. Needless to say, it wasn't pleasant, but the upside was since I was almost going cold turkey, withdrawals were shorter. Even so, I found that after the main withdrawals faded, I still had that general "shitty feeling"; dysphoria. Nothing was interesting or exciting, I was depressed almost always, and in general it just felt like life sucked, and was going to continue sucking for, at the very least, a long time. I'd get these flash cravings that made me want to do shot so bad, I almost couldn't take it.
This lasted for a month strong, and gradually from that point, got a little better. Most days I'd wake up feeling like shit, but every once in a while I'd have a good day. Only in the past week or two has it really felt like things are getting better, and my cravings have died down. I've also started taking a few nootropics (vinpocetine, huperzine a and DMAE), so that probably has something to do with it. I imagine that if I stay clean, it will still be a little while before I feel fully recovered.
Your situation is different than mine and unfortunately your time-frame is probably going to be longer. This is because you tapered off which, while no doubt being a much less terrible method and oftentimes essential, means that you've been keeping opiates in your system all this time. Thus, even though you're taking small steps in the right direction, your body isn't really recovering a whole lot. Once you aren't taking anything at all, then things will start to get moving, and you'll probably experience all that I've described above.
It's true that the real difficulty isn't so much getting clean (although it is indeed very unpleasant) as it is staying clean for two weeks, one month, six months, etc. This is because it's very easy to get discouraged in this time period. You think, "I've been clean for a month already, and I still feel like shit, and life's not getting any better than it was when I was getting high...in fact, it's getting even worse!" You wonder, "what's the point in staying clean if life isn't any better?", and it can be really hard to overcome those thoughts and not cave. Without a doubt, the only reason I made it this long is because I moved 4000 miles away from where I used to live, and I have nowhere to get any opiates. Otherwise, I probably wouldn't have made it more than a week, at the most.
If you're serious about quitting, I recommend you try to cut off contact with your connections. Tell them, "I quit, please don't sell me anything anymore, even if I come back begging in a week". Hopefully they'll respect that, though some won't. If it's a viable option, move somewhere where you can't find anything even if you tried. Other than that, try to keep yourself well fed and nourished, try to make it a habit to drink plenty of liquids, get some vitamins and maybe some nootropics like I mentioned above, try to focus on important things that you've probably been neglecting, like your health, and just try to be strong. Try to find a hobby or something you like doing that you can devote your attention to. This is key. If you lie around all day thinking about how much you wanna get high, I guarantee you won't last long. Just try to find other ways to enjoy yourself and have fun. Easier said than done, I know...if you're having trouble with this part, you might want to check out some NA/AA meetings. I was in rehab once and it was mandatory to go to about 5 or 6 meetings a week. After 2.5 months of going to a meeting basically every single fucking day, I can't stand them, and I didn't really find them very helpful in the first place, but some people swear by them. And I can see how it would help to be able to talk to others who are going through the same thing as you.
One last thing: the last thing you want is to substitute one addiction for another, but I find that doing other drugs CAN be beneficial. Again, it also can be very detrimental. Don't kick opiates just to get hooked on benzos. Don't give up being a junkie just to become a tweaker. But I smoked a pretty good bit of weed throughout all of this, and I found it to be very helpful. When I wasn't overdoing it, I found it would help to break up the monotony of the day and help with the dysphoria. If I'd smoke it all day then I'd just get lazy and eventually I felt like it wasn't really helping. I also would drink from time to time, which was nice, but again, I'd regret it if I overdid it. Overall, if you're going to use any other drugs, especially if they have the potential for addiction (which I don't recommend unless you're positive you can handle it), my advice is this: stay sober as much as you can. Save getting high for those "holy fuck!" times, where you panic and start freaking out, depression hits you hard, and suicide actually starts looking like a nice alternative. Most of the time, a nice joint/bowl (if you smoke) or a drink or whatever will help you to snap out of it.
And that's about all the advice I have. Good luck, and remember that people kick drugs every day, and some of them do stay clean, at least for a long time.