Being in a long time relationship myself (6 years now), I say discuss it with her first and see how she reacts when you weigh her cons in the discussion.
If she continues to be like that and doesn't give a damn about your opinion and doesn't see that she has to change her attitude, then move on. You're just 17, you don't need to be strung up with someone who doesn't appreciate you (She crushing your interests and thinking low of you is completely antagonizing in a relationship).
Plus she also cheated on you; it doesn't matter how "soft" was the cheat, she did it and there's no telling if she won't ever do it again, or if it won't be worse next time.
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CPU - i7 8700K 3.7 GHz (4.7 GHz turbo) 6 cores OC'd to 5.2 GHz with Watercooling (Hydro Series H110i) | MB - Gigabyte Z370 HD3P ATX | Gigabyte GTX 1080ti Gaming OC BLACK 11G (1657 MHz Boost Core / 11010 MHz Memory) | RAM - Corsair DIMM 32GB DDR4, 2400 MHz | PSU - Corsair CX650M (80+ Bronze) 650W | Audio - Asus Essence STX II 7.1 | Monitor - Samsung U28E590D 4K UHD, Freesync, 1 ms, 60 Hz, 28"
