Welcome back -- I'm on a similar journey as you (27, bout 330lbs)... finally ready to commit to change and lose this weight for good. Its hard as hell some days, but it's worth it.
Been on and off going to the gym over the past year, and went again last night and busted my ass for the first time post-xmas. Was tiring as hell, but felt great. Heading out now for a bike ride too... small steps seem to all add up!