How to sort out my impression?

I started uni on saturday and i think already ive made a really bad impression. Yesterday two blonde girls who i wouldnt normally even give the time of day to (but i have been being nice to because its uni and were being grown up and stuff) said they didnt like me, and then an hour later my boyfriend broke up with me. so i sat in the smoking garden crying hysterically. How do i sort out my impression???