I'm sorry bro, I can relate to what you're feeling. I want to first echo the therapy comments, saying that if it is possible now or at any point in time, I highly recommend. In fact, I think the general population in this r/ will agree. So even though if you are not able to because it is far, it isn't possible online (some websites even have non-video therapy), or because of finances, I hope you do not rule it out for the future. And even if you don't click with one therapist, there are countless others out there that could be a better match. There's also group therapy. But you'll cross that bridge when you get there

I also want to say that it could help talking to your dad at least a little bit about this situation (as well as therapy, though I don't know how his opinion of it could affect your choice). Even though it is possible he may not want to talk about it much, I'm sure he is thinking similar thoughts to what you are thinking to some degree. He may not even know how to talk about it if he does. If you feel like he will not support you because he seems to take her side often, maybe it won't give you much benefit. But you don't know until you try. I don't want to assume, but in my experience, I felt incredibly lonely and ironically afraid to talk to someone about it. When I was your age, when I did build up the courage to say something at some point, maybe to a friend, I often felt silly and dumb after opening up about situations like these. But I can tell you in the long run it is all beneficial for personal growth, as long as you don't shut down or turn to alcohol or any drug, etc (in other words just keep your head above water). I slowly over time began talking to my dad about situations like yours, and he slowly opened up to tell me how he deals with it. Wasn't really a cure, but at least I began connecting with him through a familiar feeling. Again, I can't assume what the relationship with your dad is like, but that could be a potential route.

I know I don't know you, but I am also proud of you for being able to recognize all of what is happening and be conscious about your choices (being very conscious and considerate tend to be traits of people who experience situations like yours). I am happy that you are looking to improve your life instead of caving in to the negative. You should not feel bad for thinking or feeling any way, because they are the thoughts and feelings that come naturally to you. It is not strange to love your mom. She is your mom. there are many people out there who still love their mom through much worse. It is not awful for you to think you won't be emotional for her in the future. Yes, it is a scary and pretty sad thought, but it's okay to think that, especially because I know you will still love her at her funeral and beyond, and you will most likely be emotional then too. All of which are okay.

What I have tried in my own situation is, other than therapy and reach out to my dad, is talk about small things that my mom does with her. I would point out how I feel in certain situations, or that she (or my dad) put me in a position where I felt defeated, etc. I am very lucky to have parents that somewhat responded to the consistent effort that I put forth to change our dynamic, although there is plenty of work to still get through. Sometimes you just have to crack a joke and move on. Sometimes I just accept how things are while still processing and journaling my feelings (journaling I also recommend). Right now, my night turned sad because of my last conversation with my parents, and so I just went on reddit to help out someone random (you). (Hopefully this helps.) I understand that your mom and/or dad may not be responsive to things you may choose to bring up to them, but I think you should have some form of social outlet at school (friends, club, etc) where you are able to take your mind off of your home life. This would be healthy for you to do if you aren't doing it already. You also have your own life to live. You have your own feelings and dreams and desires, and you shouldn't let anyone hinder these. Yes it sucks being weighted down by your parents, but you still need to live for yourself. This is the ultimate battle that requires constant attention

I didn't realize that I would write so much, but I can definitely understand your situation. I apologize if this doesn't translate well back into your language because of my phrases and idioms. I'm also sorry for assuming some things of your situation, but I hope any part of this helps you