you should avoid caffeine if you have serious sleeping issues, get sleepy during day and feel very tired, that is a sign of adrenal exhaustion and cortisol over production. the last thing u want to do is drink coffee. get that fixed first.
another reason not to drink coffee is lyme carditis and heart block. if u have very bad irregular heart beats, high pulse, etc... u don't want to do coffee it will make things worse and u can end up in the ER.
....on the other hand, when u feel better, there's no reason not to drink some coffee, but in the morning only! i always do, i sleep well at night, have no heart issues any more (boy i had MANY) and of course... it helps with the mind and concentration, tastes well... do i have to go through this ?
but no sugar or milk in the coffee. i just put stevia.