Need some relationship advice...?

ok so here it is.. im 21 and my "girlfriend" is 20... we started hangin out since last year.... we met through a girl i used to mess with (her ex best friend) .... well everything was fun... we always went on crazy trips and had a shitload of fun... as time flew she started liking me as i liked her but i didnt wanna ruin the friendship... now shes happy bcoz im her 1st bf.....however we dont have an established date we just winged it lmao... now recently weve been arguing bcoz she gets stupid jealous of even friends i knew before her... she wants to know who im texting, whos facebook im on, and she basically wants me to tell her what time i took a piss (sarcastic but u get the point) im startiing to get annoyed and i told her and she said she'd work on it... i dont bother her for anything... i think of it as none of my business.... still she hasnt changed for the past month.... and everytime i suggest we go on a break or give space she cries histerically so i shut off my phone.... shes acting crazy shes even making suicidal threats like "goodbye this is the last time youll hear from me" ... ive been around these type of girls so i let them talk the talk bcoz i cn telll if there serious or not.... and sometimes she even drives to my house no matter what the time may be and honks the horn if i dont talk to her..... she never wants to leave my side which is cool sometimes because ive always been a loner but sometimes shes too attached to where i cant breathe... its killing me but i know shes a good person with a big heart... i dont wanna ruin her.... i dont want her first relationship to be know as horrible... i do love her but sometimes i just want to be alone.... she always includes herself when i want to just take a random drive alone.... and then when im mad she always wants to know whats wrong after i tell her i dont wanna talk about it 100 times,,, i dont take her for granted but shes too dependent on me and i just dont want to one day not be around and have her being shut down until she sees me again... she claims she cant function without seeing me for a day and she actually cries about it.... seriously? one day? idk what to do its driving me nuts... i sometimes want to hang with my friends some of which are females but she just says "oh go be with them then" after she knows im not that kind of person..... oohh and when i talked about being active in college she flipped...i want her to understand i want a social life. she cut off all her friends after i told her not to and that she'd regret it....i just need some advice... am i just going crazy bcoz she says it always my fault.... but i think differently.... anyone with any advice would be great....