Hello~You possibly could have some misplace vertebrae in your lower back, I suggest maybe seeing a chiropractor, he/she will probably take an x-ray to see what is occurring, then discuss the results with you and if they can help. After a few adjustments, if this is the case, you should start to feel better.
I have also put in a request for this to be transferred to our "Men's Health" forum, they may have more insight as well.
I am also a 22 y/o male if that helps.