What could cause allergy-like symptoms and not be allergies

For several years now, the dr. has been treating me for allergies. BUT even when I take the meds as directed, I still come down w/respiratory infections, at least once per year. On top of that, I take thyroid medication, a daily vitamin, and additional iron supplements yet I'm still exhausted when I get home from work. (The last time I went to the dr he said I was "down a pint," meaning that there is a low red-blood cell count, as I underestood.) Also, I haven't been able to smell anything or taste anything for months now--everything tastes/smells like either wet sawdust or ashes, whether I cook it or eat out, whether it's gas being pumped into the car or flowers. Any comments?? TIA.

I don't have any idea but what I can tell you a couple of things that will improve your health:

Clean up your diet. The American diet is horrible. Stop eating anything with added sugar. Sugar weakens the immune system. Stop consuming carbonated beverages and stop eating fast food, processed foods, and foods with artificial ingredients, including artificial sweeteners. Once you take control of cooking all your own food you will know for sure exactly what is in your diet.

Trust me you will be healthier and have more energy. Fresh fruits, veggies and lean meats are just what you need. Drink lots of water also.

Secondly, get a flu shot every year. There has been recent study in children that proved that when kids get a flu shot they get less colds. It works the same way in adults. It supports the immune system. There are those out there that have the idea vaccines aren't good for you but the research just doesn't back them up. If you have immune system problems (you appear to) it makes sense to do the most that you can to support your immune system. If you take away the things that may be harming your body it will have a better chance at working correctly.