If you have to limit your use to "every 7-10 days" you're already addicted mentally. At this point you might as well either stop completely while you get your life straightened out, or cut the foreplay and do the drugs however you damn well please. They're going to kick your ass eventually, might as well admit defeat now or keep going and get it out of your system. There's no shame in either; some people learn through observation, others (like yours truly) only learn that the stove is hot after they touch it.
I'm an ex-daily user of oxys, heroin and suboxone who went to treatment by choice a year ago and stayed completely clean for 6 months, but I've had success with being able to use drugs and drink on occasion. The way I've been using opiates is only when the situation naturally arises, like when I have nothing to do for 2-3 days. So far that's only been 4-5 times since June. I have a box of pills in my nightstand that I could take whenever I want, but I don't want to because I have other shit to do that's more important to me than getting high. In fact, it's been two months since I've taken any opiates, and I wouldn't even be thinking about how long it's been if I wasn't writing this post. I haven't done any other drugs other than alcohol, opiates and one hit of weed at a concert since my inpatient stay.
Be warned: I am not your average case. In the year since I went to treatment I've moved to a new city, far away from everyone I've ever known. Most people don't have the opportunities that I've had recently and have to stay abstinent forever once they've been addicted. Besides, there's no guarantee I'll even be able to handle my shit 6 months from now. This is just my experience and where I'm at right now.