Start by dicing and sauteing a half an onion in a hot pan with some olive oil. Once the onion begins to cook, it converts the starches to sugar and sweetens up. Same for garlic, but add it in just as the onion is done because garlic will cook within 1-2 minutes. Also you're using too much tomato paste. Try using 1 can sauce + 1 can small diced tomato. If you still want to thicken it up, add in 1 tablespoon paste at a time. It shouldn't take more than 2 Tbsp. Fresh basil gives the best results. Don't overkill your sauce with too many different spices, choose one, either basil or oregano. Mushrooms are nice, but they add a woodsy flavor, not sweet. And lastly, dont add in your cheese until just before you serve it.
just my 2 cents
Edit: forgot to add in, only use 1/8 to 1/4 teaspoon sugar. the sugar is used to cut the acidity of the tomato, not sweeten the sauce.
just my 2 cents
Edit: forgot to add in, only use 1/8 to 1/4 teaspoon sugar. the sugar is used to cut the acidity of the tomato, not sweeten the sauce.