<human>: Can you give me the gist of the text in a nutshell?

I am a female college student working full time, and I have no idea where to start. I was very active fall semester 2014 due to being in the marching band, where I was around 145 lbs which was a normal, healthy weight for me. I was that weight all through high school as well, involved in band, show choir, theater. I am now 185 lbs, 5'6. I'm not unhappy with myself, I have a lot of body positivity, but I want to march Drum Corps International starting in November and I want to start prepping my body for that. It takes a lot of endurance and physical fitness. 

Since I'm working full time and I'm a student, I am looking for quick, affordable ways to lose weight. Something like slim fast or a similar program would be great. I have no idea where to start and any information would be incredibly helpful. Is there a program you've tried that has been really successful? I have used MyFitnessPal in the past to track my calories and it told me I should be around 1200 to lose a pound a week, and though that's what I eat (and even below that....I remember typing in 800 cal for one day...), I'm not losing weight. I'm assuming this is/was due to shitty food, fast food, school lunches, irregular meals, etc.
<bot>: I'm trying to lose 40+ lbs, in a cheap, effective, safe way. I need some help! Thank you!