Certainly in your past life you must have had been a devotee of the Lord, otherwise you wouldn't have felt like becoming a nun at such a young age. Anyone who has a natural tendency for rejecting sense-gratification is considered to be advanced or liberated in spiritual life. Your appreciation of Maya as false and Krishna as the only reality is a great asset. Nobody has ever gained anything by becoming a tool in the hands of Maya, but everyone has become eternally happy by serving Krishna.
The feeling which you had by becoming compassionate to the fallen bum is very good, but the best way to deliver a bum is to revive his dormant Krishna Consciousness. If you can do that then give the bums good food and shelter. If you cannot do that, then simple supplying food and shelter, is serving the Maya. But there is no benefit to serving Maya, as you know, as it is all false, temporary or illusion. We are concerned with Reality, not Maya, and that should be the object of life.