Hey Marie,
Sounds like you are a machine! although 2 hours may feel good it might be tiring out your muscles, if your at the gym for longer then 1 hour your most likely just waisting your time because your muscles wont gain if theyre tired.....
But if your eating 800-1000 calories you should drop weight very fast but i recommend eating closer to 1000 even up to 1400 (average woman should eat 2000) and even more if working out. if you eat 5-6 small healthy meals everyday 3 hours apart and 3 hours before bedtime and working out regularly you will most definatly lose weight.
My recomendation is to warm up either eliptical, stepping machine, running etc for 15 min to get heart rate up, then do exercises for your main portion of your workout. having days dedicated to certain body parts for example my weekly routine is upper body one day, lower body one day, abdominals one day and cardio one day, all warming up on the stairmaster and running for 20 minutes afterwards.
For more info on my workouts, diet, weight loss tips and tricks etc check out my website at www . auntie-ana . blogspot . com (of course no spaces)
Anyways good luck and I hope to hear from you!!
xx