My dog had several bouts of very severe pancreatitis but hasn't had an attack for several months.
I have to strictly control the amount of food she eats so weight everything. She's on Royal Canin 'Sensititvity control' wet food, which has a fat content of 6%. She can't tolerate dry food, which definitely aggravates the condition in her case. Also if I feed her on chicken for too long she gets a very upset stomach.
I allow her no commercially made treats except a very small amount of Thrive pure chicken treats, which are made with just chicken breast meat. She can't have this every day though, and it's kept for her teat ball which I give her when I have to go out and leave her alone.
She also can't tolerate cooked vegetables but can now eat raw carrot occasionally and loves a small amount of water melon without the pips, which she has most days, after our afternoon walk.
She was on several - about 4, I think - different medicines when she was first diagnosed; sorry forgotten what they were, but is now on a low dose - she's a small dog - of 'Zitak' once a day; Zitak is a dog antacid medicine, which keeps her on an even keel.
We have in the past tried stopping the Zitak but it seems she's going to need it for the rest of her life as it definitely makes a difference and keeps her pain free.
Before we got it under control she was very lethargic and couldn't walk for long before she would be wanting to be carried. Now she can really enjoy her walks and her runs off lead in the park and hasn't wanted to be carried at all for ages.
The last time she had her bloods done there were still signs that it hasn't gone away, so it's definitely a life time illness but I have found it can be managed.
I hope you too can manage to get it under control for your dog. It's horrible to see them in pain.