How to make a sandwich without it becoming “slippery”

Hi, I am 16. My mom passed away so I don’t really have someone to teach me how to cook anymore. I really love turkey sandwiches, but whenever I make them they are always really slippery. How do restaurants like cook the sandwich with tomato and lettuce and cheese and stuff without it becoming so wet?

I like spread mayo on both sides, and I cook it over the stove assembled, but I feel flipping it can make the stuff fall out or the bottom piece of bread under the tomato will get really wet and can break?

I feel I see girls on tiktok and they make their sandwiches all assembled over the stove top like I do. But, theirs actually like stays together and looks really good LMFAO. I mean, mine still taste good I just dont know how to make the bread not soggy.