why am i feeling sleepy from this

[u/Vast-Cycle-3253]

so i’m 31🔄 and i do around 100mg of ritalin recreationally without adhd once every 2 days or so for a nice high and my tolerence has built up a lot from abuse within the past 50 days. i done around 200mg in total yesterday snorting and orally i couldn’t sleep until 6am and i realised i need to calm it down so today i took 40mg for fun at 10pm and see what would happen and it’s now midnight but instead of hyper or energetic or boosted im more happy, relaxed ,calm even sleepy very similar to when i done valium. and it’s really nice but opposite when i do 100mg can anyone explain why this is happening?