This is for me as much as you -because my motivation and mojo have left the building except I really don't care all lthat much... So Im gonna talk to myself - and you can listen... (except I don't have a wife, though could use one cuz I am a slob)
remind yourself why you want to lose weight... your motivation has to come from within you... and they are your reasons alone... do you want to wear that european style swimsuit at the pool (and if I'm anywhere i the vicinity, unless you look like an olympic 22 year old swimmer, I will mock you

- behind your back

) fo you want to look like a stud for your wife? to be around for the dog, the kids, the cute next door neighbor... Find your reason for wanting to lose weight and keep that as a reminder - on the mirror (though if it is the neighbor, you might want to keep it in aplace the wife can't see - well unless ya'll ar einto that
Every few times of doing what you're supposed to be doing... reward yourself... the reward is up to you... keep a calendar on the fridge and put gold stars on it - and see how many gold stars you can get in a row... it takes 28 days to build a habit... and 28 days is doing the same thing 28 days in a row... taking it one day a at a time... you will get there....
Don't focus so much on the scale, it's not your friend and it's tempremental... We all obsess over it way too much and too m any people judge their day based on the reading and that's just bull... Focus on you behavior... building healthy eating habits, building a sensible exercis habit. Focus on how your clothes are fitting, how you're feeling... Focus on the behavior and the numbers will fall into place.
I've read too much on the negative impact of diet soda so i would strongly suggest losing them... drink water - flavored water - homemade iced tea... and keep the soda as an occassional treat...
If you do exercise regularly - you can eat more calories
good luck and feel better... like smokey the bear used to say -only you can prevent forest fires, and only you can make yourself do what you need to get the results you want.