Write down in every matchup how your supply and the amount of drones you got at 08:00 every game. It feels more fun to improve when you have something concrete to improve.
If you see someone is attacking you, make 3 overlords first, then units. If you make units until you're supplyblocked you will most likely end up with a smaller army.
There is probably so much you can improve so I think it's good to make a plan for yourself if you wanna get insane really fast. Week one should be all about macro. Don't scout, don't be agressive, don't micro. Just focus each day on different stuff.
Day1: could be injects. If you miss an inject by 3 energy before 10 min you should already think you've lost.
Day2: could be larvae spending and always produce one/two/three overlords before you spend the rest of the chunk of larvae.
Day3: combine this shit together.
The thing about this is that you really need to put your focus where you want it to be. Isolate yourself from the game, don't put the focus on what your instincts want.
Or you can just play casual and sell your soul to the Devil and he can make you the new bonjwa. I believe you have to go to a crossroad and dig a hole to put a box with a picture of you in it for a demon to show up. 10 years of success in this game could be worth it.