Sometimes the body simply gets very sensitive to particles in the air. It's not exactly an allergic reaction, it's more like a tickle and irritation by something you breathe in. It's going to be very hard to eliminate everything in your house/bedroom that will set you off. Start with your bedroom and eliminate the things that may be harboring dust particles like drapes, fancy pillows, and duvets. Wipe down everything as best you can. Give it a couple of clean days and see if you sleep better. Use a damp mop on the floors if you don't have carpets. If it seems to help, and you have carpets, think about getting rid of them. For this first extra clean dust eliminating cleaning, if you can get someone to help you, it would be very good. It might even be worthwhile to get an air filtering system for your bedroom. If you can clean up where you sleep, then it will help ease things for you for the rest of the day. don't use perfumes, bath powders or soaps that have a fragrance. Be careful about what kind of detergent you use in the washer. No softening sheets either. No air fresheners. I'm sure that you have already thought about most of these things, but sometimes it's easy to forget a few things. Everything that you can eliminate, makes it easier to tolerate other things. You may never be able to completely eliminate everything, but you can make things much more bearable. Don't forget to change that filter on your air conditioner or furnace either. Keep your window and doors closed as much as possible. Fresh air is nice, but often it has air borne particles that will irritate. I hope this helps some. From my own personal experience, I am a terrible housekeeper.....and I pay for it by having to cough more than I should. We took up the carpets that were in the house when we bought it. That helped a lot!!! The previous owner loved poipourri, and I think the walls and carpets would coated with the stuff!

UPDATE: I'm now off prednisone and the asthma seems to be subsiding. I guess all the measures we've taken (steam-cleaning carpets, HEPA filter, allergen-neutralizing spray, washing walls, opening windows, etc.) must have reduced the cat dander to a level my body can handle. I appreciate everyone's thoughts and advice. At the same time I have to wonder why many people were so quick to insist on drastic solutions. (I should add that my husband agreed -- he was ready to rip out the carpets from day one.) To me it makes sense to tough it out for at least a couple of weeks, assuming there isn't a true health emergency. I suppose I have a reasonably high tolerance for living with low-level misery, as long as there's an end in sight. If things had taken a turn for the worse I would of course have taken appropriate action.

Becky: I think I see what the confusion is. The OP said he "just" had seed put down, and I had it in my head that this seed was still germinating, and in any case certainly is not long enough to mow. I reread his post and see that he said "in the last month" these weeds have been growing, which suggests the new grass is older than I thought. My bad. So given the grass isn't quite so new, I'd just pull the weeds out. I could get the ones in the photo in 10 minutes. I do hope the OP updates us on what happens. A little more on type of seed, etc. would be nice, too.

If it's baseboard heat you should be able to remove the fasteners and lower it.