I'm a big salad fan and usually either bring one or just bring ingredients. Do you have access to a kitchen at work? What about a fridge? I'm a big fan of prepping Sunday nights before work. I chop lettuce, spinach, kale, and toppings (carrots, raddishes, raw almonds, seeds, dried cranberries, sundried tomatoes, whatever!) and separate them into little baggies. When it's work time I can just toss a handful from each bag into a zip lock and be good to go. I usually throw dressing on too and just let it hang out for a few hours, it's a good way to make 1 tablespoon go a long way.
Favorite work meals and snacks:
1) Hardboiled egg and sliced veggies (carrots, celery, cucumber)
2) Canteloupe and prosciutto
3) Canteloupe or honeydew (I straight up bring an entire melon into the office, cut it in half, and eat it with a spoon. Co-workers think I'm insane).
4) Yogurt/Kefir Mess.
Generally Fage 0% with frozen blueberries. If you toss frozen blueberries into the yogurt container in the AM, by lunchtime they've melted and left a little bit of juice. I try to keep away from sugar but a drizzle of honey is good too. Kefir with some sort of fruit works too. You can also bring an apple, slice it up, and add yogurt or kefir. A few flax seeds and you have protein, fat, and fiber. Once made the mistake of pre-mixing psyllium husks, kefir, and frozen blueberries. Do NOT do this. The psyllium husks gel up and it was like kefir psyllium jell-o. That was a fasting day
5) Deli meat/cheese or deli meat/fruit
6) Back when I ate carbs (sigh) La Tortilla Factory tortillas made great wraps. They have like 12 grams of fiber, too.
7) If you're really stumped, Lara Bars. I hate them though because they don't fill me up and they're around 200 calories/10 grams of fat each and it feels like a waste of a calorie allotment. Some people love them and do well on them though, so more power.
8) Cottage cheese and _______. Works with everything!
My best tip and the one that worked well for me when I had a long commute, no kitchen, and a long shift, was to bring a bag with a few pieces of fruit and protein-y stuff. A large container of Fage and an apple and a pear could keep me busy for years.
9) Veggie burger (cooked at home so you can either heat it up or eat it plain), preferably Amy's Texas Burgers because they are AMAZING, on top of chopped broccoli with a generous dollop of sriracha or tabasco. I buy chopped frozen broccoli from HEB (Texas grocery chain) that's cheap and easy to dump into a container, or if I'm inspired I can stand around stir frying.
I hate planning meals too, so I try to keep cals reasonably low at work so that I can splurge, or not, when I come home. Good luck to you, it's a bummer to figure out meal plans but if you're not surrounded by food at work it can be great for your diet! I always lose big when I am in a place that does not have access to a kitchen

!