Training & Nutrition - Confused

I started a regime where I am eating about 1800-2000 calories a day on average and exercising regularly. For my workout, it is usually a 3 mile run, and I do this 3-4 times a week. When the weather warms up, I'll put the SPD's back on my mountain bike and do some 20-30 mile rides(which will suck, its a 32x18 singlespeed). My daily life is usually pretty fast paced, going class to class and doing physical labor a few hours a day. I have gained weight, despite doing all of these things. It is frustrating, and discouraging. I have, however, slimmed down a little, but I want to be lighter. What are some suggestions?

I had a similar problem: in trying to get to a healthy body weight of 160, I plateaued at 170lbs. The advice I got from many of these forums (look for Danno's threads) was that I was eating too few calories for the amount of activity I was doing, thus shutting my fat burning machinery off. I ate 1800-2000 calories and was stuck. I started eating between 2200 - 2500 high quality calories (complex carbs) and the weight started to drop off again. I'm closing in on 160. Chris Carmichael's 'Food for Fitness' helped a lot.

Good luck.

I started a regime where I am eating about 1800-2000 calories a day on average and exercising regularly. For my workout, it is usually a 3 mile run, and I do this 3-4 times a week. When the weather warms up, I'll put the SPD's back on my mountain bike and do some 20-30 mile rides(which will suck, its a 32x18 singlespeed). My daily life is usually pretty fast paced, going class to class and doing physical labor a few hours a day. I have gained weight, despite doing all of these things. It is frustrating, and discouraging. I have, however, slimmed down a little, but I want to be lighter. What are some suggestions?
How much do you weigh and how much have you lost so far? I doubt if you are counting the calories very accurately, or maybe you're cheating a lot. I don't see how an active (or even inactive) person could fail to lose weight on 2000 calories/day, unless you're pretty small.

If the SS "sucks" why don't you get a different bike? I doubt if you'll ride much unless you enjoy it.

I concur. Try keeping a food diary. Make a note of everything you eat for a week. Either you'll figure out what you're eating that's keeping you from losing, or the discipline will keep you from eating whatever it is.