Thanks to both of you. I may be just confused on my terminology. Bart, is what you describe below a left-handed flam? In a left-handed flam, is the right stick the one that hits first? In that case, it's the right-handed flam that I am having trouble with. In any case, the solutions you have both suggested are clear. Thanks!
Position the drumstick with the right stick low, 1 or 2 inches above the playing surface, and the left stick higher, 8+ inches above the playing surface. Drop the sticks at the exact same time. The right stick will hit first and will be softer; the left stick will hit last and will be louder. There's your Flam. Work on controlling the space between the two strokes, but always think of dropping the sticks, resetting your position each time before playing another Flam.
Once you work on this for awhile, your Flams will become more relaxed and even. You can work on speeding them up and alternating Flams.
Bottom line: Go slow and stay relaxed; work on clean sounding Flams.
If you can get with a private instructor, I highly recommend that you do ... even for just a few lessons. Let the teacher help you and teach you to teach yourself.