Congrats on day 2 aflo. The first few days of physical withdrawals are they toughest, your body is not used to being sedated all the time and it needs time to heal. Consider yourself fortunate to be able to sleep...insomnia is sometimes a problem early on too.
Just remember that withdrawals are only temporary....you should start feeling a big improvement in the upcoming days. If you don't, consider seeing a doctor - some of us are deficient in things that can be improved with diet, exercise, etc.