Read Dharma Mittra's response:
First you must listen to your own heart: unchanging, effulgent, and golden. All the answers you seek lie deep within you. It is so easy to forget this in our fast-paced culture, which constantly demands our attention. But I always teach that, in reality, the wisdom you seek is inside you, and by accessing it you will quickly find a course of action that serves you and everyone around you. Yogic practices help you change your gaze just slightly so that you may draw your focus within, where the truth lies, and everything becomes crystal clear. Then you will know what is best for you and how best to manifest your passion for serving others.
To help you realize your inner wisdom, it's important to look for guidance in the yamas and niyamas—the ethical rules of yoga. Without these, there is no hope of realizing your own inner truth. By building a foundation in the precedents of the yamas, which are compassion, truthfulness, contentment, and surrender, you will quickly be able to quiet your mind and experience a profound peacefulness. From this state of bliss, you can naturally access your inner wisdom and find the answers you seek, and more.
In terms of your studies, I recommend that you study the kriyas, which are ancient yogic techniques that purify the physical and astral bodies of the practitioner. They are known as the shatkriyas, or the six cleansing techniques. You should also learn about the mudras (seals), bandhas (locks), Pranayama (breath control), mantras (mental seed power), and of course the asanas (steady posture). An excellent guidebook for these many techniques is the classic Hatha Yoga Pradipika.
Be aware though, that there are certain aspects of these practices that you cannot learn through books alone. So as you deepen your practice, you must seek out the care and guidance of an experienced teacher, or guru. Through deep intuition, you will know what teacher is right for you and you will quickly be able to learn both the physical and therapeutic benefits of each technique. Once you have done this, you will have all the tools you need to help others as you so desire. With sincerity and humility, you can and will certainly become a "celestial doctor." And you may not have to travel too far to do it.