Being humble does not mean that you avoid having success in your ministry. Never get the wrong notion that being a success means being proud. There are many successful heroes of faith in the bible and they are very humble.
Start seeing yourself growing strong in your ministry. Visualize yourself as succeeding and not failing. Discouragement may hit you but that does not mean that you have to take it lying down.
God has created you to fly and not to crawl, to climb and not to fall, to succeed and not to fail. You are made for your God-given assignment and you must succeed. Keep soaring!