Being vegan is sucking the protein out of your muscles making it impossible for you to lift. Pretty soon you'll look like a victoria's secret cover model minus the nice big expensive boobies.
Seriously though, I would recommend using www.cronometer.com
for a few day's, maybe a few weeks to see what's what with your diet. It sounds pretty good, but when i first decided to become a vegan and do the raw foods thing I thought I was eating a ton of food, and it turned out I was only getting around 2000 calories a day, and most of it was from fat. Now I keep my fats pretty low, eat around 4000 calories/day from primarily fruits, and make sure I eat 1-2 pounds of greens/day (Kale, spinach, chard, some lettuce). I also eat a lot of corn, sprouts, tomatoes and that kind of thing. 4000 calories/day from mostly carbs should make me obese, but I think my body just burns through the fruit really well.
Any major transition in your diet will naturally effect your lifts, usually adversely, but by now you should be seeing things turn around, so track your diet so that at least you know what's going on with it, and keep us posted.