My advice is no matter how good are your programming skills or your product, if you're not selling, it's useless to be that good.

Get some good selling skills and human skills. The only reason why that other crappy software that you're competing with sells for millions is because the guy is better than you at selling it.

Maybe you should study and invest in learning how to sell and then give another chance to your software (that should be a good one after 4 years).

Stop developing, start selling.