With less T, there is less T-->E2 production and skinny guys will have low E2.
You probably have some bone loss, Dependant on how long you were in that state.
Guys who start TRT can have problems if they have cortisol and/or thyroid problems.
Please look at the thyroid basics sticky and note symptoms and check your body temperatures as suggested.
100mg T cyp per week will be enough for your body weight.
Please post all lab work here with ranges:
LH/FSH - should have been done before TRT started
Do you get cold easily?
Get hot easily?
Outer eyebrows sparse?
Do not use iodized salt?
Time line for above. Was cold now hot?
What is time line for your symptoms of low T or other issues?
What happened prior to this?
At day three, E2 levels may be overwhelming.
Please inject twice a week.
Did you read the things that damage your hormones sticky?