well that's a problem mentality. unless you've gone to an experienced trainer or you've really done what it takes to be thin & healthy (constructing a good WORKING meal plan, working out consistantly) then you can't say that you'd be "happier" doing what you're doing...
a lot of people have the common misconception that in order to be thin and healthy, you have to go through hell and be unhappy... but this is really just the opposite...
if you've reached a goal, if you're thin and healthy n' look good, you generally will feel good physically and emotionally.
but, in the rare occurance that a person has "been there n' done that" and STILL reverts back to being overweight, then so be it.
the problem is is most people are just uninformed about how to reach physical goals because of all the bullshit fad diets and workout plans out there. the only true way to reach goals (this is practically universal to everyone) is to first follow a basic foundation, and then become more specific oriented fitness-wise. doing all of this takes either the use of an experienced fitness trainer, or time to educate yourself.
never try the bullshit fad diets you see on TV.
/end rant.