Feeling very sorry for herself

Hello , my name is Tilly, I had a perfectly good life. Running about in the woods every day. Playing with my brother Sprout, fighting and pulling on toys. Running and jumping on the bed, window sill and furniture. Then suddenly my mumtook me to the vets and when I came out suddenly! All walks are on the lead, she wont let me play with Sprout, im not allowed to jump on anything. Oh and my tummy hurts... Life is terrible, help me! Love Tilly