What do you do to feel better when you have a bad cold or flu.

Ok So a few days ago my cold started coming after sleeping over my friends house her cousin had a cold and she wanted to sleep in the same room with us.She's 6 years old and i think i caught it from her because she slept on the floor with us and she was coughing on me the whole time and my friend told me not to worry because she's almost better.It didn't look like it she even vomit on me a bit and i wanted to go home and shower but my friend said if i left she said that she was a afraid i wouldn't see her for a long time and i have a heart for people.So i changed my clothes and stayed there because i felt bad.I Think i have the flu now because i have been feeling weak and i had a huge headache i even fainted.Please tell me if you think its the flu or just a cold.If you guys are sick i hope you feel better soon.