I need help to try and stop my mom from harrassing me about my fraternity

[RutgersPIKE]

So as a first year student at Rutgers University this past year, I was one of only four people from my graduating class to be attending the school (and all the rest were girls) and only one of six total from my school to be attending there this current year (and I was not to close to those guys at all) so I knew pretty well that I was going to be meeting new people. Going into school I was against joining a fraternity but after the first night of my wonderful college year I knew I wanted to join a fraternity and I know exactly where I wanted to pledge (see if you can guess what it is), however to my mom it was always ALWAYS school first. Now at rutgers, freshman cannot rush a fraternity or sorority until the second semester of their first year so I did have a lot of time to think about my decision and the whole first semester I got really close to a bunch of the brothers at my fraternity of choice, but still there was this big thing of getting this past my mother (who might be smaller than me and can be the sweetest woman in the world, BUT you DONT piss her off and I am still deathly afraid of her haha yes I know im a mamas boy) and she was 150 percent against greek life, especially me, the first person in the family to go to college, to join in the wonders that is greek life. So second semester came and still after many many attempts to convice my mom to let me join she still said no, but i was not going to let this stop me (bad idea). So i secretly attended all the rush events and accepted my bid, thinking I can keep it quiet till the end of the semester where I would prove to my mom that fraternity life would not affect my grades. Well this secrecy lasted oh a whole four hours as I got a very angry call the next morning about my decision. So after a few hours of debate with many harsh words thrown around I had finally convinced my mom to let me continue with pledging and that if I didnt keep a 3.4 GPA that I would have to pay for my entire college fees, instead of just half. So I finished pledging and now I am living home for the summer, but still I can see the dissappointment in my mom about my decision and this beats me up inside, even though my decision to pledge was the best I ever made, but I still cant convince her that its not all about partying and "paying for my friends" (thats the biggest thing she uses to piss me off) but that it was about the lifelong brotherhood, and being apart of something more than just me and that this is my family when Im away from home and now I have 60 best friends in the entire world, my family means the world to me especially my mother since we went through a lot just the two of us (no this is not a will smith reference) and i would really like to ease my moms feelings of dissapointment, please fellow Greeks, anyone else ever been in this situation and can anyone offer me some advice? Thanks

RutgersPIKE