I was like that in my first few years after I prayed the sinner's prayer. I don't think it is healthy to experience frequent doubts. It has to do with spiritual growth and maturity. I haven't felt any doubts in the last three decades. I can sense the Paraclete in me at any time, all the time.
See How to get closer to God and grow in faith.
See How to get closer to God and grow in faith.