Hello everyone. This might be a little lengthy.

Quick backstory.
Over a month ago I had a nervous breakdown. Anxiety, panic attacks etc.
My boyfriend broke up with me during my nervous breakdown. We lived together in a foreign country where I'm not originally from.
I ended up going back home for counseling. I feel a lot better.
I meditate daily, do a gratitude list daily and practice affirmations. I try to ignore things that are negative and stay in a positive mindset. It's been working well.

My younger sister came back with me to this foreign country and is staying with me for the next 3 weeks. She has been very supportive of me up until we came here. She has anxiety and social anxiety so she understands how I'm feeling.
However..

Ever since we came she's been constantly complaining about everything and not enjoying herself. Constantly complaining that everything is too expensive, she's too fat, she's too ugly, everything sucks, this and that is a tourist trap. She criticises me too. She says the following almost every day: you speak too quietly, you're too sensitive, you're weak, you get too easily annoyed, calm the **** down etc.
Then she told me that I ruined her first days here because I was crying over my boyfriend (we came back to the apartment I lived in with him.. which was triggering of course). She said that I'm weak and I'm letting a man control how I feel and that I should just get over him. She also mentioned that on the way over here I got afraid cos of "a little" turbulence (I got teary-eyed and was shaking). She told me: It's like you're broken. You're so weak now. The smallest thing breaks you.

Today we left to go sightseeing 20 minutes earlier than was planned. She was speaking to her new boyfriend on her computer. When I said we had to go she told me to shut up while she was talking to him, was sighing and complaining that she had to go and that she'd rather not. Ended up blaming me for not telling her the correct time (Which I did), then sulked all day until a stranger told her she was beautiful then she perked up. I'd been trying to speak and lighten the mood and never got any response from her.
We finally came home and she told me that I had a bad attitude all day and that I should fix my attitude and learn to calm down.

When in reality I was smiling and enjoying myself, while she was complaining about everything.

I'm at a breaking point because I don't know what to do with her. I tell my parents about and they do nothing. Tell me to be patient and not fight with her.