Hi! I had to go through this switch too!! I was on Humalog for 6 years, then was switched to Novolog and have been on that for the last 4 years and still going.
Remember that insulin is a hormone. Your body will need time to adjust to the "new" think you are putting into it. Yes, you are still putting insulin into your body, but it's a different type, and yes, it does make a difference.
I don't think you have anything to worry about, but try taking a blood glucose reading when you feel like this and see what they number is
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