Once your 18 is done, then start the 16. Once thats gone, start the 11. etc. etc! its a good way to ween your self down.
What I do, is I keep about 4 carts worth of the higher stuff until I get used to the lower stuff. That way if I feel like I need a little boost, (stress trigger) then I have it available.
Its worked for me. Got me from 36 to 18 already! I have taken it very slow though.