The problem is over time, you get sensitized to things and what hasn't bothered you, does now.
In terms of particulates like resin dust, a good N95 will do the trick since there are no organic vapors to deal with. You can use the paper ones from Home Depot, but they're not that comfortable. Look to Amazon or industrial supply for a 3M half mask, probably under $10. It's soft silicone, warms to the face and I can wear them for hours on end. You can get N95 filters for it for a few bucks. Beauty is, you can use the mask forever and change the filter, or if you're using other stuff, add a OV cartridge.
In terms of CA, you're out of luck, just need ventilation. It's the isocyanate family and there are no filters that'll work. The only thing close is to use a paper N95 and wet it down since the isos bond with water immediately. Same goes for urethane resin 'cause it's the same family. .
Jeff, I got to break it to you, but if you're doing a lot of work, it's time for real ventilation. You can get a squirrel cage blower (so you down explode if you're spraying laquer) from Dayton on eBay for great prices. Some dryer duct work and fittings and you can set it up to vent out a window. I have two system set up in benches that go through the wall, but I work with this stuff for hours every day.