you will know when is to much...your test levels wont recover anymore...15 cycles im surprised you have decent levels.you have actually had them checked? test levels i mean?
the reality is if you are eating like you should be while on cycle, it will take years off your life, stress does that to a body that is used and abused...
i think 3 a year is too many....you already did 15 cycles!? geez....even if you did 3 months off, 3 months on, back to back to back....thats 3 cycles over a span of one and a half years...i would stick to 2 cycles a year, preferably one a year