This too shall pass

There is no reason why you should abandon hope of success in the yoga. The state of depression which you now feel is temporary and it comes even upon the strongest sadhaks at one time or another or even often recurs. The only thing needed is to hold firm with the awakened part of the being, to reject all contrary suggestions and to wait, opening yourself as much as you can to the true Power, till the crisis or change of which this depression is a stage is completed. The suggestions which come to your mind telling you that you are not fit and that you must go back to the ordinary life are promptings from a hostile source. Ideas of this kind must always be rejected as inventions of the lower nature; even if they are founded on appearances which seem convincing to the ignorant mind, they are false, because they exaggerate a passing movement and represent it as the decisive and definite truth. There is only one truth in you on which you have to lay constant hold, the truth of your divine possibilities and the call of the higher Light to your nature. If you hold to that always, or, even if you are momentarily shaken from your hold, return constantly to it, it will justify itself in the end in spite of all difficulties and obstacles and stumblings. All that resists will disappear in time with the progressive unfolding of your spiritual nature.

Ref : Letters on Yoga Vol. III