Firebelly Newt not eating... please help!

[Ladybast]

I've had my Firebelly (his name is Iov) for about 5 years, he was always a good eater, taking 1 cube of frozen bloodworms every other day. A few weeks ago he stopped eating. I have tried live Blackworms, and he's not the least bit interested. He was always a chubby little thing and very healthy. His temp. was always kept at 78, and then I read that was too high. Last week I dropped it down to 75. I just tested the Ph, which is 6.6, and am adjusting it now.
Do they hibernate? Please help, I love this little guy.
A few months ago he lost one finger, I think it was from climbing the screen cover. I used bacitracin and peroxide on it until it healed, he was fine for awhile after that, and now he has this problem.