Devotees: Maharaja Parikshit

Q. Prabhupada told us to "Chant Hare Krishna and Be Happy". I have been chanting the maha mantra since two years and I am following the rules and regulations but I am still very unhappy. I guess that there is a problem somewhere with me. My life is a mess. Krishna gives me too many tests which I can't handle. I have been struggling with my spiritual life and I am tired now. I am helpless.

Q. Maharaj Paraksit was protected by Lord Krishna from the womb of Uttara because he was a spotless pure devotee. Now if that is the case:
a) Normally it is told that such an elevated devotee doesn't have to take a rebirth and that he goes directly back to Godhead. Why should Paraksit Maharaj take a rebirth?

b) If he was saved from the womb by Lord Krishna, when he had a death incurred by a sin, why was he not saved by the Supreme Personality?