Flash Help!

[JKeena]

Alright, I'm getting really mad now! I've been shooting sports for a long time now and never had this problem until I bought a Vivitar 283 and Sto-fen diffuser. All I've been getting back from the lab are black slides with hints of neon ceiling lights. Lately I'm usually shooting at 1/125 sec and f22 (according to what the vivitar tells me to do at 3-5 feet). Obviously something is wrong and I've been doing alot of testing but I'm running out of money here! I work 8 hours a week!! SO, can anyone tell me what I'm doing wrong? I got a couple of shots where I got a hint of a rider in the frame. I think I shot at f11 on those. So should my f stop be way more open? And if so, how do I know exactly how open when the flash is saying [5ft /f22]? This is getting VERY FRUSTRATING because I've been shooting some nuts good guys and they are psyched to do it for a camera but they want results and I got nothing to show. PLEASE HELP! If I get one more dark roll of flourescent lights I think I'm going to.. I don't even know! Anyway, thanks for any help you can offer. -Justin