Hi Sandie,
I think your reaction sounds pretty normal. You've made excellent progress since going onto insulin, so it's natural to feel some worry now that you're being taken off (some of) it. Don't worry, you don't sound like a nutter!
The main think to remember is that it's YOU that's made the improvements, not the insulin. YOU were the one who took control and went low-carb; lost the weight; started exercising. The insulin is simply a tool that let you control your bloods while you transitioned into this healthier way of life, and until your body settled into its new "rhythm". That's obviously been happening - you've massively dropped the amount of insulin you need to inject, and there's no reason not to continue dropping it - in fact it's desirable.
My opinion would be to give it a try and test a lot. If your bloods go higher than you'd like, then think about whether you should re-introduce one, two or three of the injections, perhaps with lower doses. Discuss this with your DM, but if you have target blood sugars that you want then this should be your main guide - i.e. don't get railroaded into accepting higher levels than you want. But really, it's worth giving it a try in my opinion.
Finally, a massive WELL DONE - sounds like you've made excellent progress! Keep it up and you'll be off ALL the insulin soon - imagine how good that'll be!