I think I would try just adding the cardio first before increasing your calories and then if you don't see a change then up your calories. If you do both at once you won't know which thing it was that you needed to change, could be that your calories are okay you just needed to add the cardio.
Up your calories.. I have JUST been thru the VERY same thing.. I was eating between 1200-1500 cal a day and was getting alot of exercise.. and I actually started to gain a tiny bit.. three days ago I upped my calories around 200 - 250 a day and this morning I was down 2 1/2 pounds..
soymilk is not always a better alternative ( to cow milk yes, but to water, no ) if you drink commercial brands like Silk, they have a lot of crap in them, even 8th continent which is better then silk, but Eden Soy and Westfarm is much better.
just read your ingredients, you should know what they mean, if it had High fructose corn syrup, carragenan, etc. leave it.
It is a funny thing. I posted a similar question in calorie counters and 24 people looked no replies.
Ok - normally I would have just read the post and kept on moving because everyone has already suggested the things I would have mentioned. But it would be rude of me to just read and run at this point. The only other things that I could think of don't really apply towards you (not getting in enough protein and/or not journaling - both of which you seem to have a handle on). My advise would be to listen to the other posters! I especially agree with Jen - it's important that you change up one thing at a time (calories or exercise) so that it will be easier for you to determine which is causing the weight loss slow down.
But it would be rude of me to just read and run at this point. The only other things that I could think of don't really apply towards you (not getting in enough protein and/or not journaling - both of which you seem to have a handle on). My advise would be to listen to the other posters! 
I especially agree with Jen - it's important that you change up one thing at a time (calories or exercise) so that it will be easier for you to determine which is causing the weight loss slow down.