Self Control

It’s a subject I’ve been contemplating for a while and it came up again in our class at church this weekend: self-control. 

We were discussing it in terms of being a fruit of the Spirit, but the truth is that self-control is one of those things we often try to conjure up in our own strength. We try to deny ourselves the things we realize are a point of overindulgence but often end up giving in to the very cravings we are trying so hard to tame. At least I know I do. So where is the line between the two? How can I know my self-control is the Holy Spirit kind and not the kind destined to eventually fail? 

I don’t have real answers yet. I find there are areas of my life I see the true fruit of self-control. And there are areas of my life that I struggle, try to impose my own limits, and fail. But the subject is on my mind and in my prayers a lot these days. 
Any insights out there?