Im so done with my parents. ADVICE?!

I feel like they don't love each other anymore. When my dad does anything my mom sighs and gets annoyed with him, and she's happier when he's gone on business trips, and gets stressed when he comes back. They've been married for twenty years, but I'm only fourteen. I hate being in a house where there's constantly a bad energy. But my dad loves my mom, sometimes he just doesn't know that some things he does really bothers my mom, but she won't say anything about it! She talks to ME about it instead of him. I don't want to hear about how much my dad annoys her, it's not fair to me. It isn't always like this, we have our good days, but I feel like the bad days have outweighed the good days by now. Any advice?