serious weight loss tips

Amanda
Hi ladies and the few gentlemen that may be on here, 
I'm looking for some advice on how to lose weight, I'm an avid junk foodie, I like my junk food, but I don't eat many meals and I eat big meals when I do, which is the exact opposite from what you're supposed to do, I know. I'm aiming to lose 50-60lbs over all and maybe about 10 lbs in a month for my birthday. I'm 5'6", 20 years old and weigh ~200lbs, I think being in a relationship, getting comfortable, and my unhealthy habits finally catching up to me was the cause of my weight gain in the last year and a half And I know I'm not healthy and in shape. I would really like some tips to change my lifestyle but in a slower way, not just bam no more unhealthy stuff and exercise all the time. If anyone could give me some tips to gradually get into this and then some tips to keep it going since I always have an issue with staying motivated it would be appreciated. (Also just a background piece, I don't really drink soda, it's rare that I do)