Firstly

that people have let their guard down and are not distancing at the super market. I'm seeing a lot of the same, as are my friends all over the world. I think every country has a section of the population that is in denial.
Secondly, please don't be upset or hurt by people laughing because you are being cautious. I have a thread on here about people commenting on me, pointing and laughing at me, and I've had a boss who told me not to let him see my face in the morning because my ugliness ruins his day. I was involved in an accident and have indentations from where my face was broken as a result, and I have some burn marks on my face from an abusive ex who would put his cigarettes out on my cheeks.
Now, I realise this is nothing like your situation but I mean to show you that I'm used to people pointing and laughing rudely when I'm out and about.
The worst is that I overhear parents telling their kids to stay away from the weird looking girl- I don't think they should be teaching their kids that. I imagine what they'd say to their kids if they saw someone disabled or with an amputated limb.

I've had people in grocery stores audibly say that if they had my face they would commit suicide. It's sad that people can openly mock another human being for no reason.
I always make a point to make eye contact with those talking about me and smile the warmest smile I can. Sometimes we need to remind
others we are human and we are nice. It snaps them out of their own bubble and makes them stop. Sometimes we need to remind
ourselves to be gracious because they don't know any better and it's not their fault that this is their limited thinking.
In any case, they're laughing because you are being sensible and cautious whereas they are being reckless with their lives and those of others. You should hold your head up proudly and let those words roll off of you, because you are the one in the right and they will be grateful for people like you who are helping to fight the spread of covid.
Don't let anyone's ill-informed opinion and bad manners hurt your feelings.
Okay, I'm going back into my hole. Every time I post on this thread it turns into a mini-rant!