Judgmenl posted...
basically every meal ends up being some combination of protein + starch.
I mean, even within that, there's a ton of potential for variety. There are lots of protein options, lots of starch options, and - most significantly - lots of options for seasonings, sauces, and vegetables to round out the meal. There's a world of difference between using eggs for a quiche, in shakshuka, or to make spaghetti carbonara, even though it's the same protein every time (though carbonara does add some pork). Don't hesitate to look for new ways to use familiar ingredients.
Judgmenl posted...
you end up gravitating towards the same 3-5 things and when living alone you eat those things a lot.
That does indeed happen, though. Even liking variety and making an effort to mix things up, I don't think I've got more than 15-20 recipes I bounce between, just because there are limits to the number I can readily call to mind whenever I think of how to use a given ingredient. If you get in the habit of keeping a folder of recipes, though, and making an effort to add to it periodically, it's not that difficult to branch out.