Motivation...

I have always been really good losing weight and having motivation but lately I can’t seem to keep my motivation. I’ll get super motivated one day and the next I’m over it. It’s never been this hard for me before. I’m in a super healthy relationship that just makes me so happy that I start to not care about what I eat. (Which is why I’ve gained my weight back) I have a chart that I made that each time I lose 10 pounds I get a reward and once I lose 40 pounds I get a really big reward! Does anyone have any tips to help keep me motivated or even just good work outs that slim you down fast? (I already do cardio and weights)