I know exactly what you mean by doing 30 min of housecleaning & then being wiped out for the rest of the day. I've been there! It went on for me for 13 months before I finally had a breakthrough!

For me (& I'm not saying this is what's going on with you), I finally find out through an immunologist that the "moderate mucousal thickening" and the mucous retention cysts (in My right sphenoid & ethmoid sinus areas) that were all showing up on my MRIs ... could be helped by OTC and Rx meds. And ... to my surprise! for me, those sinus issues seemed to be causing MANY/MOST of my post-covid symptoms: extreme vertigo, severe weakness & fatigue, hand tremors, terrible headaches, vision issues, incoordination & gait issues.

Within a week or two of starting 3 of the sinus meds, after 13+ months of suffering with long-haul covid issues, my gait improved markedly & I was able to return to a normal speed of walking! I was finally getting my energy back! I still had visual issues & vertigo in my head/eyes, but that almost completely went away after my immunologist added a 4th sinus med.

So, after 14-15 mos of covid symptoms, I am now almost completely back to my old self! I still have a little vertigo here & there every day, but it's so much less than it was. The same with my tremors. But the biggest improvements have been in my gait, my strength, my fatigue level, and my energy!

So, even if sinuses specifically aren't your issue (I didn't know they were for me!), listen to your body, don't do too much. Take naps. 15 min of exercise (housework or whatever) may be your max for a year or more. Don't wipe yourself out for the rest of the day ... or for the next 3 days ... by doing 30 min of housework. Focus on what absolutely MUST be done. Use paper plates so you don't have as many dishes to do. Make a bigger meal 1 day & freeze portions to make quick meals for yourself on other days when you're feeling tired or need to do something exerting like mopping, vacuuming, or laundry.

Keep pushing to see a dr who can figure out what will help you.

Love & blessings.