I had a salad yesterday, then toast today with cream cheese.
I am always home too, I'm also veggie but there will be meat versions of much of what I have
Sandwiches do feature regularly but I try to vary fillings so as not to get bored because as you say that leads to eating other food to satisfy
Also wraps, soup (I tend to batch cook my own and freeze what I don't eat the day of making in portions that are perfect for my assigned soup mug), a small portion of pasta, quorn sliced fillets with a splash of hendos relish is nice, crisp breads or crackers with cheese or veggie pate, quorn mini savoury eggs are yum as are the cocktail sausages.
Also salads sometimes "basic" just salad veg with maybe some cheese or boiled egg wedges, I can quite happily have this undressed with just some garlic grinder to season, or a splash of white vinegar but sometimes I'll fancy a dressing of some kind, Mayo or salad cream or in the summer I might buy in a dressing as I'll have salads more, or I'll make a batch home made and keep in the fridge (I save and wash my jars for this kind of thing or home made pickles)
Also Cous Cous/pasta/rice salads - again I'll make a batch usually although it's quite easy to make up a small portion of Cous cous to use in a salad.
Eggs - tons of ways to do eggs quickly, light tasty and nutritious and low cal too. Omelette, scrambled, tortilla, boiled (I love cold boiled eggs with a little sat for each bite or Chucky eggs - hot boiled eggs mashed in a cup with butter and salt), or baked. Fried on occasion too.
Things on toast - the usual beans, tinned spaghetti but also I love creamed mushrooms, tomatoes sliced with a little garlic grinder, sliced hard boiled eggs with a little salt, avocado with a dash of lemon juice and a pinch of basil, or even mashed banana on toast LOVE that
If I'm hungry I might also have a small portion of yogurt and some fruit, I'm trying to eat healthier myself. Sometimes I'll have a tunnocks teacake (fewer calories than you might thing given how rich they are) or a small ice treat - the joys of ageing - I've been overindulging in magnums of late but they're sooo calorific and after a wake up call I switched to ice poles and mini milks instead.
Water or milk to drink - milk isn't as high cal as people think and makes you feel fuller for longer as it's high in protein. Love a glass of cold milk! Admittedly skimmed, not because I'm saintly I've just never liked the creamier milks.
Today i'm having a pot noodle. With home-made water. 
Yea I like a pot noodle/pot pasta sometimes too
I think if you want to avoid the same boring sandwiches or snacking, you need to include lunch in your meal planning and prepare some things in advance, at least for some of the week.
I'd agree with that
@VictoriaLudorum - ohh is there a recipe for the mushrooms bourguignon?
@OohImBlindedByTheLights are you having the same exact thing every day?
If I have a big lunch I'll have a light dinner and if I'm planning a big dinner I'll have a light lunch - yes you need a balance but being too restrictive can make you feel deprived and more likely to go "fuck it" and reach for the family bag of crisps!
@misslomi you're clearly a cheese fiend like me! 
Or souped up baked beans (fry an onion with some garlic and chilli and add the beans)
I've been debating starting a thread about this, I add to almost everything to make them better. I like the sound of yours though I'd omit the chilli.
I've added to beans at times - marmite, hendos relish, sour cream, herbs...
If having on toast I'll add one or more of the following - grated cheddar, sweet pickle, gherkins, salad cream, pesto sauce (this one works really well - use it instead of butter on the toast)
Tesco do a lovely 3 bean chili soup, in the fresh section. It's really tasty and very filling too, and only about 150 calories a portion. That's become a WFH staple during the winter, often with a piece of cheese on toast on the side.
That reminded me - there are some less well known tinned things that mean knocking up a quick and filling lunch are much easier, eg tinned mixed beans in a vinegar dressing for a salad, tinned lentils - Dahl or ragu, tinned ratatouille is a great topper for baked potatoes, toast, pasta