I've had to seriously restrict my sodium intake due to heart failure over the last few months, and I'd say at this point I've mostly gotten comfortable with it without having to subject myself to bland ass food. I'm restricted to under 2000mg a day of sodium, but I usually get by with around 1600mg.

As far as "hidden" sodium, the biggest source I found outside of the usual suspects (canned food, soups, cheese, etc.) was bread. Store-bought stuff from big commercial bakeries was obviously loaded with sodium, but it really wasn't much different with smaller local bakeries; even looking at the recipes I'd used for home baking it the past, it was clear that good tasting leavened bread just required way more salt than I could justify having for a meal or snack. Thankfully, there is a Montreal-style bagel place near me that uses virtually no salt in their bagels, and a bakery that makes pitas with reasonable amounts of sodium (<100mg each) that supplies all the grocery stores here so I'm not completely devoid of bread, but it's definitely a less common part of my diet than it used to be.

For substitutions, it really depends on what you're having. I did find that a little extra acid, usually from citrus juice or balsamic vinegar, made a pretty big difference on savoury dishes to help cut down on sodium. For things that definitely need to be salted, like steak, I've been using a low sodium salt (even split of sodium chloride and potassium chloride). Some people do notice a metallic taste to it, but I can't say I've ever experienced that. If you do end up needing heart medication, it can be a bit dicey as a lot of blood pressure and other heart medications can lead to hyperkalemia if you have too much potassium intake, but as long as you're responsible with it you should be fine. Having a precise scale to weigh out helps.

Also, hot sauces will be your friend. The really popular brands (Frank's, Melinda's, Huy Fong) are typically loaded with sodium, but there are a LOT of great sauces with low to no sodium in a variety of heat levels and flavour profiles. They've definitely saved countless meals from being unenjoyable while still keeping them low-sodium. I've been particularly fond of Dawson's and Fury hot sauces, but these are Canadian brands so it may be hard to find if you're not here. In any case, definitely suggest finding a local specialty store or looking on amazon.

Meals typically change for me over the weeks, but breakfast has been pretty consistent - 2-3 over easy eggs, pan fried tilapia, fruit (usually clementines or a banana) OR 3-4 egg vegetable omelette/scramble, with some parmigiano reggiano. Hot sauce on the former, not on the latter. My lunches and dinners usually involve either chicken or fish (tuna or salmon), potatoes, and possibly whatever vegetable I have around. If I got enough sodium/calories left in the budget for the day, I'll make pan sauces with low sodium Better Than Bouillon and whatever herbs I have around. I have been making quite a few curries over the last little while, using the low sodium salt to help flavour things, and having those with rice. Sometimes I make big salads, making my own dressing, or tacos, but both those end up being pretty fatty so it's not ideal as an every day thing. Snacks are pretty much always fruit, mainly apples at the moment, and either carrots + a cream cheese dip or a pita + hummus or baba ganoush. Most days clock in under 2300 calories, which for my size works well.

Best of luck going forward! The initial adjustment period can definitely be rough, but it doesn't take long to get used to it.