I don’t know of such a precedent in the Old Testament.
Thank you for your candour; and I am glad to hear that, after turning to atheism, you are working your way back to God. Finding your way back to God is always preferable to being an atheist—even if that means joining the Catholic Church!

However, if you feel that your prayers are like “talking to air molecules,” there is a reason for that. Paul explains it like this:
Hebrews 11:
6 But without faith it is impossible to please him: for he that cometh to God must
believe that he is, and that he is a rewarder of them that diligently seek him.
To be able to pray to God with a minimal of faith, you need to have a spiritual witness that He exists, and hears and answers your prayers; and you can only obtain that by returning to the Church which you left, the LDS Church. The reason is that the LDS Church is the only true Church of God in the world that He has established in the latter days, and which He acknowledges to be His own, and to which He is willing to testify by His Spirit. You cannot obtain that witness in any other church. Unless you return to that Church, and strive to regain that spiritual witness (that you probably had before and then lost), you prayers will always feel like “talking to air molecules”.
zerinus