No worries we have all been there.
I grew up on English muffins with canned sauce and American cheese. LOL
Sounds like maybe a few issues.
-The dough was old or not given enough time to rise. Homemade dough has just 4 ingredients. Here is what I use 500g flour, 325g water, 10g salt and 3g yeast. In a pinch I have made this dough, given it an hour or two to rise and used it with good results. An overnight rise in the frige is better though.
-Store bought shredded cheese has additives that hinder melting. Get some blocks of white cheddar and mozzarella 50/50 and grate them yourself in a food processor or by hand. A sprinkle of parmesan gives it a bit of extra flavor.
-It's possible that you continued to cook the pizza trying to wait until the cheese melted resulting in an overcooked crust.