I'm coming at this as a 33 year old man that dealt with a similar issue with both my parents and how those experiences have aged with me over the years and what i've learned from it. I don't mean any disrespect by my comment, and i'm not writing it to offend anyone. Just an observation being made based off limited facts you provided.
It sounds more like you want her to agree/approve of what you're saying rather than actually looking for her respect. Her rolling her eyes and making snarky comments based off what you're saying may be rude, yes, but I wouldn't take that as her displaying a lack of respect for you. Why? Because she's actually listening to what you have to say, even though she doesn't agree with what you're saying. Consider this snippet from your original post:
"Most of the times I don't even try to discuss anymore. I'm just saying "ok" and smiling when she tells me my little ideals are gonna vanish again."
Rude? Yes. But she's listening to you (again). She's hearing you out (again). You just don't like how she's interpreting what you have to tell her. However, if you sat down with her and tried to speak with her and she dismissively responded to everything you said with a fake-smile and an "ok", you'd probably feel worse.
Now, i'm speaking with absolutely no context as to your relationship with her, but i'm guessing there isn't any verbal/physical abuse here, just typical parental concern being displayed in a passive aggressive manner. She's your mom and a mother is always going to have an opinion on what their kids do (good or bad), no matter how old their kids become. You're always going to be her baby. Maybe she's being rude because she doesn't agree with you, but that's just how opinions work, she just might be tired of talking about it. The day you speak to her about something you're passionate about and she just completely disregards your existence or dismisses you without a thought, then you'll see what it really feels like to be disrespected by someone you love. If you know it's a hot topic, just skip over it. You're not going to change her mind. If she tries to bring it up, tell her you love her and that you'd rather not discuss that topic because you know she doesn't agree with it. Good luck, hope this helped, even if just a little.