My super weakness

So, lately... for whatever reason I've actually decided I wanted to start working out. And I've started doing that. The problem is that when you don't work out for... years it's hard to get into it. I'm not in horrible shape... but I could stand to be in better. My muscles get SUPER sore particularly if I use a 'new' set... so I've taken to going to the hot tub to relax them... every time I go, even if I'm only in the jacuzzi for five minutes the next three hours are a struggle to stay awake. It puts me to sleep sooooooooooo fast.