Thanks @Miika for the mention, I would have missed the thread otherwise.
Your issues sounds really similar to mine, so here's some advice on what worked for me.
It boils down to: make it a marathon, not a sprint -- which in essence means doing really small changes, not changing everything up at once.
Get a baseline
You should weigh yourself for 1-2 weeks, without changing anything, to get a sense of where you are right now: are you stable, going up, or going down?
I was never able to keep a weight log until I found an app (Libra for Android) that displayed a reminder to weigh myself in every morning and got a personal scale somewhere really close to my phone, so when I'd check my phone in the morning, I'd also weigh in and log it.
Replace one meal with Jake
You're a high calorie dude like me (I use 2350 kcal just sitting in a chair), so I'd actually recommend keeping the Jake Light you have for later because you're just going to get hungry and splurge on crap.
That happened to me when I decided to just have 3 x Jake Original per day, because I don't really care about food at all -- and 2000kcal was way too low, I'd get cravings and such.
So, just replace one meal a day (preferably the one were you usually eat lousy -- that was lunch for me) with Jake Original, and for an hour before/after that meal, don't eat/drink anything else except water.
Listen to your body, keep a log (can be just a braindump like I did), drink lots of water if you get any headaches or weirdness.
Do this for a month and report back here with your weight log and we'll go from there.
Oh yeah, your weight log will be bumpy, so don't put too much heart in the day to day weigh ins.
When I was experimenting with other diets I used to get so upset before I understood this, I almost gave up -- a trend usually emerges between weeks, not days.