Diabetes: Am I off base?

Type 2, Dr prescribed 30 units of Lantis before bedtime, 500mg of Metfornin at breakfast, plus 1000mg of Metfornin at suppertime, and Novolog on a sliding scale depending on what my BG reading is before a meal, plus 1 unit for every 15 grams of carbs after a meal. In 6 weeks of regaining some control over my BG levels, my weight has gone up by 15 lbs (and I did NOT need to gain any). At present I've been able to pretty much eliminate the Novolog by either taking a brisk 45 minute walk or 30 minutes on my exercise bicycle, when my BG goes up to 135. Most days now I don't use any Novolog during the daytime. I check my BG before and 2 hours after every meal and most mornings it's between 80 and 105. My thinking is, the Novolog I had been using (as much as 35 units a day previously), was largely responsible for my weight gain, whereas if I instead go exercise, that'll bring my BG readings down without any additional insulin. I am keping my carb intake at or below 80 per day agaginst 1800 calories otherwise. Starting tomorrow I will up my Metfornin at breakfast to 1000mg, and I am expecting to be able to begin reducing my Lantis from 30 down to 26 and monitor my BG readings from there. So far I am tolerating the Metfornin well and expect to see my A1c's come in under 6.5 next time it gets tested. So, have I missed anything and are my conclusions at least in the ball park?