Stim tolerance goes up real fast and even if you take a long break in between after heavy/moderate use. Also if you were trying to get clean and then relapse, sometimes the guilt or "damn I just blew it again" over-rides the high. I also find that no dopamine = anxiety. Stim abuse temporarily depletes dopamine levels and that can cause more anxious feelings.
I've gone through this periods with different substances before, trust me it'll be fun again one day. You're probs just sick of the feeling and too used to how the ice feels so expectations are ruining it. But it's just a never-ending cycle with all drug use where the feeling sucks and then you go back to liking it all over again like in the beginning. Sometimes the brain takes a little bit of time to adjust to processing a substance too, and doesn't process something as well as it used to with an elongated period of sobriety.
