If I was addicted to meth, I would change my consumption method.

Its known that the faster it goes into your system, the more addictive it is.

Maybe (very careful of dosage) try taking it orally instead of snorting or smoking? It may take a few tries to switch over, but you may be able to reduce your usage that way.

If your self medicating some type of problem, you want to find out just what that problem is that your trying to get away from/ fix.