I am a chronic allergy sufferer. I feel your pain. It is absolutely true that you can develop or "outgrow" allergies at any point in your life. You can suddenly develop an allergy that you never had before. It also may be that something in your new environment is causing it. Allergy testing can give you answers, but you can still treat yourself in the mean time. Start with mild things like over the counter sudafed or claritin or something similar. If that doesn't help, take benadryl at night and see if that helps (benadryl can cause a lot of tiredness so be careful with it). I personally take Claritin D. I have to buy it at the pharmacy and it is regulated. You can also get air filters and air purifiers for your home to help clean the air you breathe there. Try to avoid long periods outdoors when the culprit is the most active. Good luck. You can treat this.
If you moved house, it could be the house, or your bedding since your symptoms are worse at night. You should look around for mold, signs of moisture, musty smells in the home, and leaks. Also, previous owner's pets can leave dander in carpets. You could wash or replace your pillows and/or comforter, they could have dust mites and other allergens. See an allergist for testing. This will give you an idea what you are allergic to, then you can start trying to find the sources in your environment. If you don't know what you are allergic to, you will be stabbing in the dark. The allergist can start you on allergy shots to desensitize. Hope that helps, goodluck!