Very insulin resistant

T1 here. I have been having the hardest time keeping my sugars down. And it seems like no matter how much insulin I take it doesn't really budge at times. This happens frequently and has been happening for years. I have been eating low to no carb, and exercising (like 2 times a day during some periods of my life). Doctors don't seem to be any help, they kind of just shrug their shoulders and run more useless tests. Anyone else ever have this and figure out the problem? For example tonight I've taken over 10 units of insulin over the past few hours and my sugar has remained about the same (it has gone down maybe 30 pts). I changed to a new site with my pump with no results. Getting very frustrated. I have been using stimulants on and off for a long time, like caffeine, nicotine (smokeless, or vapor), and via ADHD medication (I don't always take it). Could those things be to blame?