How to heal my injured tailbone?

Over the past few weeks I've been experiencing pain on my tailbone, I'm an 18 year old male. It isn't a constant pain, but its aggravated mostly when I sit down, specifically on a soft surface(My bed when I sleep, car seats, movie theater seats during Fantastic Beasts and where to find them.) It's slowly gotten worse, I am at a point where I need to take ibuprofen twice daily. My mom is an RN, and took a look at it on Sunday, she said there's no sign of external bruising, and it doesn't look broken. So at this point I don't what is wrong. My mom says it's my weight, im 5'7 and about 170(I got a little gut.) I really can't remember anything I did out of the ordinary that would case this injury. What can I do to heal it?