Vocal problem

I got the stomach flu a couple of weeks ago I used to have a vibratic sound now my voice is very shaky and it vocal cracks a lot what should I do to get my voice back into shape.

Sorry to hear that, Isaac! I'd recommend a gentle warmup like this one, along with plenty of water and rest. I know it's frustrating, but sometimes our bodies take a bit longer to heal than we'd like. If it's a struggle to sing, more rest might be needed!

 i lost 20lbs as well and i think after i lost all the weight from my sickness it took away all my muscle from my voice.

Rapid weight loss can definitely cause some temporary imbalance!

if I want to do a 30-day course in order to get my voice back into shape which teacher do you recommend

Mine or Jonathan Estabrooks' course focus more heavily on vocal technique, so I'd recommend either one!