Ok, glad you taking control of yourself as the last thing you want to do is go blind or get a limb chopped off or even worse brain damage from the lows.
I believe a controlled diet where you are eating healthy and doing similar things each day, eg gym at this time eat at that time, etc. Will help you to be able to balance your sugars even better, unless of course you going through another hormonal change everything. How old are you as I have seen when you get around 23/24 you might start to struggle finding a balance with your readings again, but that is a phase that will wear out.
Another thing you might want to look at is an Insulin Pump as this way you will have better control and it will work in a similar way our pancreas works giving you lots of short bursts of insulin and you can then do away with the long term completely. The other benefit is it picks up on your body changes exactly like you would when you going into a low, things like your body starts to sweat, increased heart rate, etc.
This way you can stop worrying too much about the insulin side of things. I don't believe you get these machines that actually have a graphical glucose monitor so you will still need to test, then again they might have ones out by now.
I would recommend you go look at
www.basicsupplements.co.za
and use their whey protein why I recommend it is because I know it works for a few diabetics and doesn't touch their readings, I know we had some issues with Evox. Rather use the unflavoured whey.
Yes you are correct the insulin can be used post workout but for you it's a requirement not really and extra supplement.
If you look at my younger twin brothers 1 became diabetic around 5 years before the other, and if you look at the muscle difference between the 1 that is diabetic and the other who was not at the time you will see how shredded and built my brother who was the diabetic first.
I wouldn't try take to much insulin or you just going to run low, so just take the same amount of units you would if you wanted to get a reading around 4 to 6, I know its nearly impossible to draw enough units or chose the right amount to get a perfect reading and you nearly always have to counter it with something to push it up a bit more.
Once again I stress looking at that pump as this way you will find a more balanced reading and not be up at 20+ then drop down to 2. This way you not going to feel as crap all the time and your new love for the gym will start to really get those endorphins going and making you feel good.
Good luck bro, if you need anything else let me know..