Hi there Mega (cool name!), first of all let's not worry about what she thinks about you (afterall there may be someone better out there for you if this goes nowhere, believe it or not!).
Let's instead focus on what YOU think about you. You know that looks are COMPLETELY subjective don't you (and there's no "ugly" in my book by the way!)?. You'll find as you get older that the people who really matter are going to find all sorts of things attractive e.g. someone's eyes, the way they smile, their facial expressions, their personality, their mannerisms.........and you really want friends, a partner who are really going to value you for YOU anyway don't you? I'm sure you have plenty about you if you can just be a little less hard on yourself and focus in on those things a little more?
And you know, maybe the no friends bit is a little more to do with the way you've been feeling as much as anything, maybe??
Do you think that you've been feeling so bad you just haven't had much motivation in making/allowing those connections, or perhaps your confidence/self esteem could have been putting some obstacles in your way? Now self esteem is something you could definately look at because there IS more about you, you ARE NOT ugly............want me to go on?? I know it might sound a lot easier said than done but..........
As for the pressure from your parents maybe talk with them about how it's making you feel and the effort you actually are putting in (a proper sit down talk!). Maybe if they understood more it would help. And who knows if you/we can have you feeling better about yourself you might feel a little more motivated and up those grades just a little.
BUT regardless, ABSOLUTELY don't think you're not good enough because of your grades WHATEVER they are. You can only do your best under whatever circumstances you're in, plenty of other people will have the same grades as you, AND there is so much more to someone than the grades they get.
REALLY hoping you can start to feel better, but we're here for you whenever you need.
Best wishes
Alison