Sweets. The simple answer is yes. Sweets are not really a healthy food, although in moderation they are ok to spice up life a little. Excess sugar tends to cause immediate damage to your teeth, raises your blood sugar, leads to more fat being deposited in your tissues, and predisposes you to get diabetes with all of its complications. It also raises your Insulin levels which makes your blood pressure wors.
Eating too much. First you need to tell us how much your eating, your weight and any medical problems. But really if you are concerned that your eating too much sweets then your eating too much!