It is completely normal for a toddler to feel anxious about doctor visits. Many parents have success by framing the injection as a way to help them grow 'big and strong,' and by keeping a special, normally restricted treat (like a lollipop or ice cream) ready as a reward immediately afterward. To manage waiting room anxiety, try to keep the child moving and curious by exploring the space together, or have one parent take them for a brief walk outside until it is their turn to minimize the time spent sitting still.