Hello. i am obsessed with health. i had a flat rash last week the size of a coin on my forearm that doesnt itch, blanch nor hurt. i dont remember hitting it either. can it be leukemia? something related to the liver? i have no other symptoms?

Not enough even to comment on it, however based on description a skin condition will be most likely, liver or leukemia always possible, not likely in the absence of other symptoms. In case rash becomes persistent or experiencing other generalized symptoms let your doc know. Health related anxiety is exacerbated by indiscriminate Internet use that lists the most serious conditions first.

It is not feasible to provide an opinion without additional history, physical examination may be some tests. It would be prudent to see your doctor to see if you may be depressed. Depression is treatable. Counter-intuitive as it may seem, exercise may help. Start with low intensity exercise such as walking and gradually increase the intensity as tolerated. Drink more water. Wish you good health!