Jelly toys are known to be very porous, making them a bit more difficult to keep bacteria free. You must always use an anti-bacterial soap + warm water to clean the toy with, then dry completely before and after each use. A water-based lube will help put an end to friction issues. Often people who use a jelly toy, will also put a condom on over the toy just to be on the safe side...
You might be dealing with a bad case of friction irritation, an allergic reaction, or an infection. There are a few things you can try before making a doctor's appointment. Take a soaking vinegar bath for 15 minutes/ 2x daily; add 2 cups of apple cider vinegar to a very warm bath, then enjoy for 15 minutes. Afterward, dry off completely and wear loose fitting cotton clothing to allow as much air flow as possible. You might also want to try applying a cold compress (cloth) to the affected area's of your vulva whenever you are at home. Stay away from any sexual activity until this clears up. If nothing seems to help the swelling or itching, go have it checked out by a doctor.