I think My Cat is Traumatized

This is my first post here, and I'm hoping someone can help me or give me some advice. About a week and a half ago I noticed that my cat Tamarind was acting strangely. He was hiding, not eating and walking strangely. He seemed to be in pain. I took him to the vet later that afternoon, and he was diagnosed with gingivitis.
My Vet suggested cleaning the teeth, but couldn't do that until he got the infection under control with antibiotics. We wound up having to make the the 30 minute trip to the vet a total of three times for antibiotic injections. On top of that, I had to give him a pain killer orally everyday. An experience that was stressful for both of us. Especially him, as he was already in a lot of pain.
Tamarind finally was able to get his teeth cleaned on Monday. He seems to be out of pain, and is eating again. However, I think he has been traumatized by the events of the past week. We used to be very good friends, but now he's scared of me. I think he associates me with the pain and stress of last week. After all, I'm the one that had to put him in the carrier and gave him his medication.
He wakes me up as usual in order to get his breakfast by sitting on my chest and purring and meowing until I give it and get out of bed, but that's the only time he lets me near him. He eats quickly, and runs under my bed immediately afterward. He tends to stay under my bed until around 6:00pm. When he comes out He's very cautious. If I make any sort of sudden move or try to pet him, he runs back under my bed and stays there for a long time. I feel like when he is out, he's constantly got his eye on me waiting to run away at any moment. He's been doing this for the past 4 days.
Before this, he was a very social. He would always greet me at the door, cuddle with me when I watched TV and "help" me with house hold chores. I want Tamarind to trust me again. It's killing me that he's afraid of me. I miss my buddy.
Has anybody has a cat act like this before? If so, how long did it take them to get back to normal and start trusting you again? Is there anything I can do to ease his fears?
I'm particularly worried because Tamarind and I are going to be making a big move from Asia to America in about a month. He'll me in the cabin with me the whole Flight, but it's going to take about 36 hours in total including layovers. On top of that, we'll be staying with my mother and her two cats until we get settled. I know the whole process is going to be stressful, and I'm worried it will be worse if he's already scared to death of me.

Well, firstly I'd have him sedated for your 36 hour trip. I relocated 3 cats and my wife and I simply gave them a mild sedative to keep them a bit dozy. It makes life a lot easier for you, you cat, and indeed your fellow travellers. your vet will want to check your cat's heart first, but this is fairly routine.

As for the trauma, yup, I'd agree he's traumatised. Don't chase him, let him come to you in his own time. Cats are remarkably resiliant creatures, but they take some time to bounce back from a fright. So show him you love him, but don't rush him. Don't overpet him, let him come to you for attention. Try encouraging him to come out of the bed with distracting bells etc, but dont be staring under the bed at him. The next few months might be stressful but in the end you'll get your buddy back.

Hi Gareth.
Thank you for your reply. Do you remember what type of sedative you used when you transported your cats? I've purchased some natural calming aids, and plan to use those. One is a spray for his carrier, and the other is added to his water.
Some of the airline websites I've been on say that they'll refuse to transport cats that have been traquilized due to possible health complications at a high altitude. For that reason, I had ruled it out. I'd love some advice from someone who's done it before. I want to do everything I can to make it as stress free as possible for him.
On another note, Tamarind seems to be getting worse instead of better as far as the trauma. A couple of days ago he was skittish, but still sleeping with me, coming out to eat and cautiously following me around the house. He's not even coming out after dark as usual today. I'm trying to let him be as you suggested, but I'm worried about him not getting enough food or water. He already lost a lot of weight due to the pain caused by the gingivitis.

if he's not eating or drinking enough then you need to speak to the vet again and explain the situation I'm afraid.

I think you need to go to the vet if it has gotten that bad. One of our cats, Poppy, is extremely timid and was abused and abandoned on a road before being rescued by a shelter. When we got her I gained her trust slowly over a few weeks of constant hiding, but one day I moved a sofa without realizing she had gotten under there and she cried and went straight back to square 1 for about a week.

I literally had to repeat everything I did to gain her trust in the first place! Her weak spot was being played with though, and as I'd found that out originally and gained her trust that way it wasn't too hard to do it again. If there's something like that which you can use then maybe it could be helpful?

Hmm, I know the way to a cats heart is usually play or food. When I accidentally scared my boyfriend's skittish cat, I gained her trust back again by feeding her treats so she would associate me with food. Maybe that would work? Feed all food out of your hand?

Hi everyone. Thank You so much for all your advice and insight. I'm happy to report that Tamarind is now almost all the way back to his old self. He's still a bit more skittish than usual, but is eating, drinking cuddling and playing like before. He's a pretty timid cat, so I think the events of last week really did a number on him.
I earned his trust back by setting my alarm early and spending about twenty minutes in the morning (the only time he would come to me) petting him and talking softly to him. The first day he ran under the bed as soon as I got out of bed, but each day he would get a little braver. Now he's following me around as usual. I just have to be careful not to make any sudden moves or loud noises.
Thanks again to everyone that replied. I was really worried about my little guy last week.