You're not really getting yourself into anything other than mental dependence (which luckily I found easy to break) and not having the drug work anymore. AKA It's over. 4-5 days on, 2-3 hours of sleep, and 80mg of IR/Vyvanse is basically what I did. You need to use it less, or at least only use it when absolutely needed. It doesn't stay very magic for long. I'm surprised you're getting much from it now. I hated the stage where all I got was gross stimulation, no sleep still, and yet I wanted to take it every day. It really sucks.
My friend on the other hand has been using Adderall IR then switched to Dex spansules then switched to Vyvanse. He takes it every day, doesn't really abuse it much (surprisingly) and he seems to still like it. Just tone down your use if you can or it's GOING to stop working, just like most drugs.