How to remove formaldehyde and VOCs from air? I don’t know how to fix the air quality in my house

I recently bought an air quality monitor as I've been really struggling with allergies and skin reactions over the past year. I've done absolutely everything I can think of regarding how I clean my bedding, mattress, i've changed my filters in my air exchange / ventilation system, I am monitor the humidity levels, and I highly maintain the overall cleaning of dust. Our house is just under five years old, and has periodically leaked due to poor construction and sealing of joints. I don't have pets and most of the surfaces in my house are hard surfaces, with the exception of my bedding in my bedroom. We also don't have the heat on in the bedroom as we like it cold.

I am a little concerned with the results of this Airthings Mini. A lot of the air in my home is labelled as "poor" due to the VOS formaldehyde content in the air, the VOC is a little too high, at around 1000ppb within the first 20 minutes of setting it up.

I will note that we don't have central heating or an air exchange, we have in floor heating only. Although I'm convinced there's moisture in the wall still, my landlord doesn't believe that there might be possibility that there is mold, and the tests are too expensive. There is a constant accumulation of dust throughout my home, and it doesn't matter how much I clean and keep on top of it...

I'm looking to buy an affordable air filter or purifier to clean my air but I have no idea what exactly I need to get. I read that an air filter using a HEPA filter won't do anything to VOC's and that I need something with an activated carbon filter. Will something like this actually lower the VOC level in my house? Or could this be something else altogether?

My symptoms within my bedroom, alone are burning and watering eyes, the inability to breathe properly as I am constantly sneezing, and have extreme face congestion, I also am having very reactive skin which has caused me to start to have eczema. - thanks