My mom is hypocritical and often unfair. What can I do?

First of all let me say that I’m a pretty good kid in general. I don’t do drugs, smoke, or drink. I get good grades. I don’t lie, sneak, or steal. I do have my moments of rudeness towards my parents, of course, (I mean, seriously, what teenager doesn’t?), but all and all I’m a pretty obedient kid. The problem is that my mom has some habits that make it extremely difficult for me to get along with her at all. We get in some serious fights sometimes.
For example, my mom has this crazy obsession over interrupting. She hates it when anyone interrupts her, which seems completely understandable. The only problem is she has this annoying habit of talking for ten minutes at a time and not letting anyone get a word out. As frustrating as it is, I follow her no interrupting under any circumstances rule. The irritating thing is that she doesn’t hold herself to the same rules as she holds me. She interrupts me all the time! When I point it out to her she says she doesn’t care about the rule and what she has to say is really important! When I still refuse to let her talk she grounds me for back talking. It is absolutely ridiculous!
Another major thing she does is that she constantly comments on my weight. I’m five four and 115 pounds and considerably muscular, so I consider myself I fine weight. Apparently my mother doesn’t agree. She keeps telling me that I’m eating too much and getting fat. Then, when I end up leaving a few bites on my dinner plate because I’m full, she accuses me of being anorexic and starts yelling at me!
What should I do deal with/ stop this irritating behavior?