Hello and Welcome to our family Andrea14. I am so sorry that this had to be such a painful lesson for you. However, it is one that we are all familiar with and many of us have suffered in the same way. Your doctor is absolutely right in telling you to wear sunscreen ALL of the time. I always recommend nothing lower thand 50SPF and to make sure that it protects you from UVA and UVB.
Of note, also be very careful around fluorescent lighting (Such as is found in Department Stores, Offices, etc.) as it can have the same affect as sun exposure for us. Lightweight protective clothing and a good sunscreen should be enough to protect you if you have to be in places that have fluorescent lighting. Also, sunglasses and a hat are a good addition to your daily routine (even in the winter months!).
I am so happy that you decided to join our family and I know that you will find that this site is filled with wonderfully understanding, compassionate, and informative people. Again...welcome!
Peace and Blessings
Look For The Good and Praise It!