"Does Leukemia usually have high WBC?"
Yes, and so does an infection and some other causes.
"swollen lymph nodes in arm pit and neck come and go"
a cancer is not going to go away on its own... and so you should instead think of "generalized lymphadenopathy" rather than cancer. Generalized lymphadenopathy is more worrisome than if there are only swollen nodes only in one region.
https://www.aafp.org/afp/2016/1201/p896.html
"High MID%"
For a blood cancer, you'd look at the Absolute count, not the relative percentage. That's because as the other immune cells go low, the MID cells go up as a percentage while their absolute numbers remain the same. That's just a math thing.
We can go over your whole CBC if you post it.