I keep on losing my voice, its been happening on and off for the past 3 years any suggestions why this is happening?

Many possibilities : The three most likely reasons are 1) vocal abuse (screaming, yelling, forcing the voice, going to loud bars and pubs) 2) reflux where stomach juice comes up into your throat without warning leading to burning and inflammation in your throat and 3) poor vocal technique with poor breath support leading to tension in your neck and throat. Please see an ENT doctor who specializes in the voice for eval.