Dysthymia (Persistent Depression Disorder) Question

Hey 7cups, I'm super new to this, and I'm not really sure how it works. But here goes:

So I've dealt with a lond span of depression in the past, about 9 months, and then things got better over last summer. However, when I got back from my usmmer travels, a really horrific thing happened in my family. I'm not really sure if this sent me back into depression or something but lately I haven't been feeling depressed so much as indifferent, tired, and overall just not happy. Originally I just chalked it up to hormones, but it's been months now and I think I might have Persistent Depression Disorder. I want to tell my mom, but she didn't take me seriously when I orginally told her I had depression. She got me help, but it wasn't the help I needed. He was a guy who helped deal with communications and understanding other people. But while he taught me how to deal with my depression from external sources, my issue was internal. To make matters worse, my mother also really does not believe in medication. If I told her I wanted to go on meds to help me, she'd freak out. Now, what I know from my small bit of reasearch is that PDD is often caused by a lack of serotonin. Obviously, if serotonin is what's making me feel this horrible all the time, I would very much like to fix my serotonin levels. So I guess my question is, how do I get ehr to take me seriously and help me get the help I need?