Am I doing it wrong?

katerams

I have started riding my bike daily, 7-8km on an inclining route. I have a protein shake (made on water) afterwards, and try to eat between 1600 and 1800 calories a day.
I have been doing this for a month or two now, making better choices on what I eat, smaller portions etc. and i'm not really.. seeing any changes from the 10kg I've already lost. I walk to and from work and am on my feet all day.
Am I supposed to be eating back my workout calories? I feel like when I see red in my food diary that i've had a bad eating day...
HELP!
I really want to get down to 85kg by next november for my wedding!