It's no crime to change your mind, and a believer might of course doubt his belief. There's a lot to be said, though, for just getting on with life, and in particular for resolving your doubts.
Having come to doubt you're on the right path, weigh the evidence as best you can. Then either stay on the path or (as in my case) get off it onto some other. What seems unconvincing to me is the claims by some believers to have wrestled with doubt for years or decades.
To people making those claims, the only thing I can think of to say is: "Isn't it time you, like, made up your cotton-pickin' mind?"
So, this is my life.
And I want you to know that I am both happy and sad and I'm still trying to figure out how that could be.