BF 11mth old WWYD- Cows milk or formula?

[wellbalanced]

My DS has been breastfed since birth, Still having 3/4feeds a day/nite.

I have a sml supply of expressed milk left- Small being 4 feeds (with few nights out planned in next month).

At mo he's not sleeping well at all so is wanting to feed more, This am ive woke in agony- He seems to be digging his teeth in whilst feeding, I dont think he's biting or doing it on purpose, Problem with latch mayb?

He is whingey and wants feeding but when i tried was very little milk, so pulling on and off making problem worse and in major pain so i gave him 4oz of cows milk.

Should i buy in some formula or just give odd bottle of cows milk (1 a day max)???

well personally I gave DS cows' milk for the daytime feeds when i went back to work - he was just over 11 months.
But even if you give one bottle a day, will that help much?

Yeah thats what i thought, ive just given him a bottle and hoping not to feed him (BF) until bed now.
He turned 11mth on Sun.

I gradually started DS on cows milk from just over 11 mths, then stopped BF at 13 months when I went back to work.

Since going back to work I am still feeding my son morning and bedtime and give him cow's milk twice a day. I was using Aptimol and taking it into nursery but so much of it was going to waste and he seemed to prefer the taste of cow's milk anyway.