I started on Friday 2nd May 2014, so I guess making it to the end of May will be a milestone for me. Good idea on recording the date - I have just popped it into my phone calendar.
You are right about the reward - I probably won't do that. I need to stop looking at unhealthy food as something good. Hopefully I will reward myself with some new clothes or something. Hopefully I will need to!
MFP is working well for me. Paired with FitBit for the activities & steps etc. I find that being able to quantify what I use vs what I eat is really helpful. I haven't heard of MyNetDiary - is that the same kind of thing?
Congrats on the 40lb loss. That is awesome!