<human>: Give me a shortened version of the text

My gf and I met in medical school, and we've been together for 10 months.

I know that its a cliché about the whole not getting along with your gf's parents thing and I also know that she just wants whats best for her daughter. But, she's constantly badmouthing me to my gf and comparing me to my gf's other guy friends (which are all better than me apparently) that her mom already known for a long time, while I feel that she haven't known me properly yet, therefore it is unfair for her to judge me too prematurely (we've only met for a few times, usually for their family dinners) and my gf says that she does it alot in general, plus she's also very stubborn about it and thinks that she's always right. Before, she even flat out asked my gf to break up with me when my gf's mom haven't even met me yet.

She would say narrow minded things like "He have an ugly face", "He is stubborn", etc. My gf usually ignored her remarks because she knows me, and knows that it isn't true at all. 
I don't think that I've done anything to offend her and make her to dislike me but she just doesn't like me for some reason. I'm really trying my best to respect my gf's mom and constantly trying to improve myself to win her approval. But it always seems like I can't please her, and that he expects perfection from me and it kinda frustrates me sometimes.

What should I do? How do I deal with it? Am i being immature for feeling this way?
<bot>: Gf's mom constantly judges me too prematurely without knowing me properly, followed by badmouthing me to my gf.