I used to have terrible allergies. I remember when I was about 13 going to my grandma's house and my aunt made me help her clean.
I instantly started sneezing and my eyes got red, itchy, and swollen. My dog allergy started around the same time. I would get a "cold" every time I would go to my grandma's (they had a dog). I went to a vet appt with her once and the vet actually told me I had allergies. I started taking Benadryl when I would go to their house, and it helped.
Before DH and I got married, we talked about getting a dog. My first allergy test, I reacted to just about everything they stuck me with - dogs, cats, dust, pollen, but not horses (oh how I have begged DH to let me get a horse lol!). We held off for a bit because the allergist told me (no lie), if we got a dog, my allergies would get worse, I would get asthma, and I would die.
He was totally serious and I was so upset. So we decided no dog. Well after I moved into DH's house, I was constantly in a terrible state because of my allergies - dust, pollen (we live out in the country surrounded by farms), mold. We got special filters for the furnace, and I could tell the day they needed to be changed every month (I would be miserable!) I finally tried another allergist. The tests all came back with the same results, but the new dr was willing to treat me. I started the oral drops and using a nasal spray and the first night using the nasal spray was the first good night of sleep I'd gotten in months! DH even had to check and make sure I was breathing in the middle of the night because I had never slept so quietly.
The oral drops are expensive, but the shots would've probably ended up costing just as much if not more because of needing to drive 50 miles roundtrip once a week for 2 years, then every other week for 2 years, then I think once a month for a year to get the shots. I administered the drops myself, obviously, and it was easy. I had to be retested every three months so they could adjust my drops, but that wasn't too much of a hassle.
I do still take a Zyrtec every day, and will have a little tickle in my nose when I clean, sometimes a few sneezes, but nothing like it used to be. I am a huge proponent of treatment, and early on is better. It really improved my quality of life.