As the saying goes...
"You accept the love you think you deserve", so have I, been in jobs, degrees and relationships I thought were suitable for my perceived level of worthiness.
Realising you deserve better is hard, and it usually takes time. Then once we do realise we deserve better, taking the leap into the unknown is even scarier. It's safer and more secure being with what we know, even if it is beating us down. But trust me, from someone who's been there a million of times and is finally adjusting her life to what she wants (instead of what she thinks she needs), I promise you that jump is worth it.
You don't deserve to be unhappy. You don't deserve to be run down, overworked, disrespected, teased, neglected, abused, and left feeling lost and hopeless. You deserve to be in a workplace that makes you smile and makes you feel like you are making a difference. You deserve to be studying something you enjoy and are passionate about (even if it's something that has a low employment rate). You deserve to be in a relationship with somebody that loves you, spoils you, supports you, cheers for you, thinks of you and treats you with respect.
You're better off being temporarily uncomfortable for a happier life, than permanently miserable in a "safe" option.