We went through some similar issues with Bo until we finally found the med combo that worked for us. Bo is one of the few that tolerated Tramadol very well. In fact, after surgery he was on it for the rest of his life with no problems. He was also on Gabepentin and Rimadyl. We started all three meds 1 week before surgery and continued after surgery.

The day of surgery, they ran blood tests on Bo and found that his liver enzymes were high. The vet said that more than likely the cause was the Rimadyl. She said for some reason it tends to affect Labradors systems and we weened him off it three days after surgery. I'm not telling you this to add to your frustration, but Maggie is a lab, so I wanted to share our experience. We put Bo on VetriLiver chews and his liver was completely normal 1 month later. The Rimadyl was certainly needed for pain management , we were just advised not to use it long term. That is one reason why we continued with the Tramadol for pain management . 

The Gabapentin had some very depressing side effects with Bo. He was very lethargic, unresponsive, and did not want to eat. We slowly weened him off the Gaba. about 10 days after surgery. Bo had pretty severe phantom pains, so again, it was needed, but not for long term. Bo's phantom pains included shaking and yelping. I'm not sure if that is what you were describing with Maggie... 

I totally agree with Cometdog on the ice therapy! It was a life saver for us!! We usually iced 3 times a day for 10 minutes. We also gave him ice cubes to eat and that really helped too. We usually did this around med time, so it calmed everyone down and we were all able to get some sleep.

We were on the phone with our vet's office CONSTANTLY for the first weeks after surgery. Do not be afraid to ask questions and get the answers that you need. You are a great pawrent and Maggie is lucky to have you!!

Once off all of the meds (except for a low dose of Tram), Bo was back to his normal, crazy self. I hope Maggie will be feeling great in no time!