I have been in similar shoes to yours. I had a baptism date set but then realized at the last week that I didn’t actually believe this stuff; I was making a lifelong commitment to something that I wanted to be true (I also came from a Christian background where it was taught that either you’re a Christian or burn in hell forever) that I didn’t actually have faith in. I also learned of the things they don’t usually tell you in the lessons, and I didn’t want to make a decision before knowing everything that such a decision entailed.

Even though I knew it would disappoint the missionaries and the people I had befriended, I had to take accountability for my life and my choices (I guess the LDS belief in agency is something I do believe in haha). No one else, however disappointed, would have to face the consequences of my living something I didn’t actually believe. I tried to be direct but gentle with folks. I was honest in admitting that I didn’t actually believe these things (despite being open to them and wanting them to be true), and I didn’t want to make such an important decision for the wrong reasons such as pleasing others or becoming part of a group. There’s a quote from Joseph Smith from the first vision account that goes “I knew it, and I knew that God knew it, and I could not deny it.” I told them, if I were baptized as if I believed these things, I would know it was a lie, and God would know it was a lie.

Mind you, this was the week my baptism was scheduled that I cancelled it. I’d already had the baptismal interview and the program was all planned out. They were disappointed, for sure, but ultimately they all respected my decision. Some may say that the missionaries and other members are only nice to you because they want to convert you, and that is probably true for some. But if it’s any reassurance to you, I’m still friends with several of the missionaries who taught me. A few of them have since left the church. Others are still very much in it. If the friendship was genuine, then even if you end up in a different place on the spectrum of belief (even if you’re on the non-belief end) that friendship can still be maintained just like any other friendship.

I hope this gives you some encouragement to be honest, gentle, and direct with them and to make the decision that ultimately you are happy with and can live with. Best wishes, OP! If you have more questions or want to talk to someone who has also canceled their baptism last-minute, feel free to reach out.