How to change from active enlistment to ROTC?

i am currently in the Marine corps Dep, and was told alot of lies from the recruiter. i missed the last 2 poolie functions because of work, and if any of you know about michigans economy, you will understand that i dont have alot of room to ask for a change in my schedule at my work. im 19, it took a couple waivers to get me in, one was for some HGH i was on as a kid. the marines ed me around, it took me 8 months too dep in, now i have to wait 6 to even ship so a total of over a year has been tied up with these guys. the recruiter called and threated to "discarge" me if i dont show up to the next poolie function. now, correct me if im wrong, but i thought i only signed up for a ship date, not accually a full contract. he also cant guarantee me the job that he did to begin with. lie after lie from this man. now i have 9 credits under my belt but only from a community collage, i had, i think a 2.5 gpa in hs. the gpa in collage should be good seeing as i had only 2 cles and had a b+ and a b- in them. i would like to stay in the corps but was wondering if i could attend the rotc at Eastern michigan, and what i have too do? seeing as this recruiter wont really help me with this.