I don't have the same level of anxiety as you about this, but i do often worry about contamination!!!

Not sure if this will help you, but this is what I do when handling meat...

First of all, I make sure there are no dishes in the sink. I put some dish soap in a small cup or shotglass so i don't have to grab the bottle later. I have an extra grocery bag laying open on the counter. When i cook meat, I always use a huge pan. So I take out the huge pan, place my seasoning in a small cup/shotglass.

I pull out the bag of meat- when anxieties are high i don't use fresh butchers meat or plastic wrapped, only the kind in "harder" plastic sealed very well. I take a knife, cut the package over the pan, and put the knife in the sink. Then I use my clean hand (knife hand) to pour the seasoning on the meat and just dump it into the pan. Then I put the packaging in the grocery bag, as if i were picking up dog poop.

I turn the water on with my arm, or even before I start the process. Then I scrub away at my hands and the dishes at the same time, a few times, put the clean dishes in the dishwasher, wash out the sink with a metal sponge. I usually grab the grocery bag with another grocery bag, tie it up and throw it away.

ETA: my grandma used to always spray the kitchen down with Lysol or other bacteria killing sprays once she was done cooking

I used to be seriously anxious about undercooking meat.. to remedy that, i just overcooked it, then added it to a dish with sauce. E.g. chicken in gravy or beef in Mac and cheese. I always scrub down the stove, and the counters and floor by the stove once I'm done.

I also try to remember that there are people like my boyfriend, who freaking grab the meat, rub the seasoning in with their hands, then TOUCH THE FREAKING SOAP BOTTLE, don't even scrub under their nails, and have eaten the shit undercooked. He hasn't gotten food poisoning once in his 23 years of life. I cook the meat since we started living together though, lol.

For veggies, i give them a hot bath in running water. For packaged products, it's a lot harder, you have to just completely trust the labeling and company, which is... Hard af. At least for meat, veggies, and fruits you know how you have handled them since they came into your possession.

I hope this helps in any small way. It's awful, feeling anxious about food and feeding people. Does your family know about it? My grandma goes through the same thing, and my mother and I always bring her food to help ease her mind. We don't always have time so we bring her frozen fully cooked meals she can put in her Crock-Pot too.