How can i put crystal meth behind me forever and not look back?

I’ve been using crystal meth for about eight years. I been thru several rehabs and had alittle clean time before. But just when i start to put my life back together i forget what that drug has done to my life and i shoot myself in the foot again. I have about a month clean and i got a job a new girlfriend and im saving money,everythings going good right now.My minds begining to wander again if anyone thats been thru this or not has any advice im listening