I'm getting tons of good information from this thread! In fact I'm learning much more than what I originally asked for and am really glad to have started this conversation. Right now I'm traveling pretty much all of summer (I start my first year of college in late August). For that reason, just for now, I am not going to change up my diet or exercise plan drastically as I'm having a hard enough time right now just staying with a consistent schedule while on moving around from place to place over the United States. With that said, it definitely seems unequivocal, at least on this board, that I should increase my calories and gain some muscle before cutting again. I will try this as soon as I get back on stable ground.
A few things mentioned here on the side... As for eating protein & "MEAT", I do! I'm not sure where I ever gave the impression that I don't, but 50% of my calories comes from protein. This means I'm eating around 200-250g a day of protein. This comes from whey powder, cottage cheese, cheese (in general), chicken, turkey, and tuna (that is in no particular order).
As for running and why I do the 45 minute cardio on the same days as I do the one mile run. At first I thought logically as you did and tried to do the one-mile high intensity run on the same day as my 20 minute HIIT session on the elliptical. It simply didn't work. Either the HIIT would tare me down so much that I couldn't complete the mile at a decent pace or the other way around. For this reason I split up the two so now I do the really intense run followed by a low to moderate intense elliptical session for 20 minutes and then a 4mph walk on an incline for the last 10 minutes. Then on the HIIT days I just do a 10 minute walk as before to end the session.
You also talk about running 3 miles at 7:30 - 8:00 min paces. I don't think so! My fastest mile right now is a little under 7:30, and I can guarantee you that afterward there is no way I could keep going for even one mile let alone two!
For interval training, configuring the treadmill is always a pain for me while running so I like to use the elliptical. It goes by RPMs instead of "mile pace" so I'll describe my HIIT in detail using it's units. I start by warming up at 70rpm. I do a "level 1" resistance for 2 minutes than switch to "level 2" for 2 minutes. At the 4 minute mark I up the machine to "level 3" and sprint at 85-90rpm for 1.25 minutes. I then rest for 45 seconds at 70rpm. At the 6 minute mark I up the resistance to "level 5" and go on with the next interval. This goes up to the last interval, "level 10", which ends at the 20 minute mark.
I want to say thanks again and I will keep constantly checking this thread and the rest of the forum for more information. I'm learning tons and am interested in anything else anyone has to input.