Hi,

It is possible to get your supply back - but your story indicates the importance of keeping up your expressing schedule if you want to maintain your supply. When your breasts become very full and are not drained, it tells your body to "turn off" your milk supply. Frequent feeding/expressing will restart it. What a roller coaster couple of weeks you have had - very difficult. You are doing a great job to hang in there. Get back on that pump, and pump every 3 hours. It can be discouraging when you get such small amounts - but bit by bit it will come back.
Getting the tongue tie snipped will be easier than you think - it's the most minor of procedures.