PLEASE HELP- toilet training has me at my wits end

[NoFucksImAQueen]

I thought we were getting somewhere but today it's like he's gone backwards. Iv bought him a coat, hung sodding tar pooling out the back to make a shelter, I give him ham when he goes toilet outside and put him out regularly.
Today he started to pee on the rug so I put him outside and he just stood there, would not go.
Just now we came back from the school pick up so put him outside, he goes for a wee, I give him lots of fuss and some ham then run upstairs to grab ds some trousers, come down and there's a big puddle in the hall. He'd obviously held most of it in then released it all in the house
He's a Yorkshire terroir cross shih tzu

He could have a uti or if he is old diabetes. I'd get him by a vet to rule out infection or illness

Oh sorry yes that would help he's a puppy. Approx 16weeks

I wouldn't expect any puppy to be reliable in the house at that age, it's still very young. Some puppies catch on with house training really quickly and some take ages to get it, it's just a case of persevering.

Just keep on with the toilet training (this is an excellent guide if you haven't read it) and he will get it.

Also make sure you're cleaning up any accidents inside with either a proper enzymatic cleaner (like the Simple Solution stuff) or a solution of biological washing liquid/powder. It breaks down any residual smell completely so they're not encouraged to keep going in the same spot.

Do you go outside with him? I had to do that with mine at that age. Sometimes they forget though. He's a baby

I used to go outside with mine and a big umbrella so he could go without getting wet!

He was really late training, despite me working hard at it. Someone horrified me by saying that if he wasn't sorted now, he never would be...

Well they were wrong. He's never once had an accident once he finally got there.