Why does inserting anything bigger than a tampon give me extreme pain? anything done down there feels discomforting.

Unusual : There may be associated inflammation of your vaginal walls i.e. Vaginitis which makes your vagina sensitive to inserting tampons and other objects. If this is an ongoing issue, see your doctor for examination and treatment

Vaganismus: There are a variety of causes. Examination and swabs may be important to look for treatable causes. There are a group of women who have pain without an obvious physical cause (vaginismus) and sometimes this can be due to psychological factors and sometimes of unknown cause but can usually be treated with various therapies. So see your doctor.

Vaginal pain: You may have dysparneuria. if you are post menopausal could be due to menopause changes /lack of estrogen. if pre menopausal could be due to insufficient lubrication due to medications, infections, trauma or muscle dysregulation. Follow up with gyn http://www.mayoclinic.org/diseases-conditions/painful-intercourse/basics/causes/con-20033293