It will give you SO much energy over time, it's quite worth it. I got a gym membership about a week ago after I used up my 7-day free trial pass, and I've been so much more energetic since I've started working out again.
Also, I had my introductory PT session, and found out two things: my endurance is practically gone, and that my body fat % is too low from trying to eat healthy, so I can eat more crap and burn it off! I really do encourage you to stick with it. I'm feeling sore already, but that just lets you know something's working!