Congrats and keep on keeping on. I started last August @ 320 , short rides at first in the neighborhood. Once I got up to 10 Miles / riide (untimed)in the flat neighborhood for a few weeks, I ventured out. It took me awhile to venture out because no matter which direction I headed, it would be hilly. My first ride out was 18 miles , took over 2-1/2 hours and included some walking. Once I ventured out, the $20 used mongoose was not up to task. Busted a few spokes. Upgraded to a Giant Cypress DX- great bike for big Clyde's - rated up to 350 lbs. it took a few months to average 10 mph. Weight this AM was 270. Current bike is Kestrel Talon now averaging 13-14 mph in the hills where I live (Northeast PA). The 18 mile ride is now down to about 80 minutes on a good day. Down in Georgia where it's flat , my rides are in the 16-17 mph range for twenty miles. Love biking. Will turn 57 in March. Keep on keeping on.