Hello 1997grrrl & welcome to the forum.
I think your anxiety is understandable, & common.
Pubs are higher risk environments.
It sounds to me like you are doing your best to keep up with the latest information about COVID-19, & with the new strain - which not so much is known about as yet anyway, so, you're being cautious.
What do they keep saying? Any symptoms, get tested. You've been doing that, even when you've been sure it's your hay fever. If you do think you are getting unnecessary tests, then speak to your GP, or see if you can call the COVID-19 number in your state. I seem to recall a little proviso, about whether the symptoms you feel are different to any usual symptoms you might have - like you know what your hay fever symptoms are usually like, so if what you are experiencing is different then follow up with a test for COVID-19.
My confusion is that the symptoms for so many things can all seem so very similar, how would we ever be quite sure we don't need a test?
It's been a long two years, & many people are sick of it.
This new Omicron variant, being more transmissible would be of concern for people who think about what it would mean if they caught it & infected those around them. Perhaps if you could think of it as you think of cold or flu. You don't deliberately catch cold or flu & pass it onto others, or feel guilty about that, (I hope), so you would not be 'guilty' of passing on COVID-19 either. You can do everything you are, & still a slight chance, something you cannot prevent, happens, & so you may pass it on.
I think everyone is responsible for how much risk they are willing to accept. You have made a decision about that. I'm sorry if people around you don't respect your decision.
I wonder, if where you are living, there is no way to get outside & walk where you would feel comfortable? If you are not doing strenuous exercise, you could consider wearing a mask.
If your anxiety is impacting your life & relationships enough to concern you, maybe it's time to talk to your GP & get a referral to a counsellor/therapist?
I hope this helps.