Stick with it. I started out at 340#s and am now down to ~222#s.
I may suggest to you that you should:
1. See you doctor and get his approval of your choice of excercise and intensity. He may give you some guidelines to follow for your current level of conditioning. Or refer you to a sports specialist of some kind.
2. Wear a heart rate monitor! Keep you BPM in your trarget range.
3. Don't over due it! (see #2) You don't want to hurt yourself or burn out.
4. Alternate days between some resitance training and arobic. (even take some days off of the bike and take a nice long walk with your lovely lady)
5. As stated before, you also have to give your body time to recover. (see #1)
6. A balanced meal plan is essential. See a Licensed Diatition(sp) to help with this.
7. ENJOY the journey. The journey will be difficult at times and joyous at other times. Lean on each other and feed off the positive energy you each have.
8. Like was posted previously:
Flip off the morons for me too!
I'll end my rambling with my sincere hope this helps in some way.
Best of luck!
Bob