Starting Fitness Blender Fit Round 2

Hi guys! A post on the community page inspired me to post my own! I'm starting FB Fit Round 2 to lose weight, and get gains. I wouldn't say I'm unfit (I've run 10Ks), but I would love to be able to do a tricep push up some day (get more muscle tone). In university I gained about 10kgs during my treatment for migraines; the meds were steroids, and since I was going through them during my 3 month break at home, it was supplemented with heavy meals from mum. Since then, I had managed to lose 8 kgs till the end of uni, and now I'm close to getting back to my peak weight again and it's plateauing despite my efforts . I aim to lose the 10kgs and get back to my original weight and get fitter in the process.

I'm not sure whether it's my exercise or my diet( I have a hunch it's my diet). I exercise 5 days a week consistently till I fall off the wagon when I see no change in the scales. In terms of diet, I'm a lacto-vegetarian. I rarely snack, and I cook all my meals fresh. I'm fairly assured I'm eating clean and healthily, however I'm not too certain about portion sizes. How much is too much?

Perhaps if I get through the first month, time will tell me who's at fault here, my diet or my habits. Here's to hoping this journey would transform me, inside and out.