I have been practicing kriya pranayama and meditation for the past two years. During the first year I felt nothing but pure joy and peace. However these days I feel quite withdrawn from activities I used to love doing but my attachment to the same activities suddenly springs back in me.
Thus I feel torn between two opposite forces and as a result my life is completely out of balance! At times I feel so free like a saint and soon enough miserable like a sinner. Is there a way out of this cycle?
It’s not unusual for devotees to feel tested in the way you describe. The main thing is that we keep moving in the right direction even if we get caught at times by negative energies or by the pulls of desires or attachments. The way to overcome these challenges is by using our will, along with devotion. In this way we are able to set in motion the energy that will produce the right magnetism to overcome the pulls of delusion.
Try to offer all that you are, including your successes and failures, to God. If you can, allow your offering to be more from your heart and not only from your mind. A good exercise to help you is to end each day, just before lying down for bed, by visualizing a fire into which you are releasing everything that has happened during the day. Feel that all your attachments, all the ups and downs of your life are being given back to God.
Paramhansa Yogananda taught that we should endeavor to be "even-mined and cheerful at all times". Try to keep this thought always with you as you go through your day. This applies to meditation as well. In the book, The Essence of Self-Realization, there is an inspiring quote by Yogananda that is very helpful: "In the Bhagavad Gita, Krishna counsels action without desire for the fruits of action. Meditation, too, should be approached in this spirit. Meditate without attachment to the fruits of meditation."
The way out of the cycle you describe is to ever keep moving toward God in every moment. By inward meditation and God rememberance, along with selfless service, it is possible to live more in the Superconscious state of awakening.