My tail bone has been hurting me so badly . It began about 4 months ago . If I sit in something hard , if I lay down to…

My tail bone has been hurting me so badly . It began about 4 months ago . If I sit in something hard , if I lay down to long , or even just sit wrong .. it’s excruciating! No I haven’t fell on it or anything . Is it something that’ was caused by child birth . This pain never occurred until after then