A frum person should not expect singing to be their (or their spouses) ONLY means of parnassa.
Even goyish singers who are very “in” today, with rare exception, are “out” tomorrow. Now with goyim, the short time they are “in” may be enough, because they can make millions during that time.
A frum singer though has a MUCH, MUCH smaller target audience, and even IF you are very successful and popular your income will never rival what a goyishe singer can make. Also, no matter how good or popular a singer you may be, there are always new people coming along, THEY will become the ones in demand, and your star will fade.
There are A FEW EXCEPTIONS to this rule, but you can count them on one hand, and a person would be foolish to think he will be that exception. My thought would be, if you love to sing and are good at it, GO FOR IT. Use the gift HaSh-m gave you, BUT – go to school at the same time to learn how to earn a more realistic, long-term parnassa. You don’t want to be a has-been at the age of 30 with a wife and kids and no income.