In my 20s, I was absolutely convinced the Christian group in which I was playing was headed in the definite direction of fulltime ministry. At one of the places where the Lord led us to lead worship, a representative for the Rhodesian chaplain corp insisted his country wanted to use us to lead worship in the bush, where the Rhodesian soldiers camped. They would helicopter us into the areas we were needed, and then out, not leaving us anywhere for too long.
We were excited about this awakening to our ministry. After all, we were getting great reviews from the fellowships that were already using us, and so we thought we were ready for a big step.
However, the female lead singer in our group, and me, began to like one another a lot, and spent lots of time together. The other two guys didn't like this, since they thought it would get our eyes off our calling. I'd never had a girlfriend prior to this, and was indeed stricken, and refused to set aside my first love.
Our disagreements grew so intense that we finally chose to disband, without ever getting to Africa.
Please be forewarned. If you are planning to do a solo ministry, it might work better. At the start, however, I believe it is best to have companions in the ministry working with you, to pray and seek the Lord, practice, choose material, etc.
As you know, routinely bands form and break up in the matter of a couple of years. I would suggest you spend time working out your repertoire and choosing the right band members before you think too far ahead. Establishing a stable unit is imperative if you want to be used by the Lord; otherwise, it will blow over after the first strong wind.
Don't be afraid of the big-headedness. There is far too much work to be done to be bogged down with that. Just keep heading forward and take it one day at a time.
BTW, today I play professionally at sipping socials, weddings, restaurants, and other light venues. The money can be better than what you'll find coming from many churches. I wish you the best.
Dave