WelshByrd my 2 older boys have both duspraxia and Aspergers. They have no learning difficulties, though.
At 8, neither of them could dress themselves at all. They couldn't use cutlery, couldn't hop/skip/catch/bat anything like that. They have never been able to learn to ride a bike/swim/play football or anything else. THey used to do things like walk into lamposts and walls and fall of kerbs and the like. They couldn't follow instructions given more than one at a time, weren't dry or properly clean either day or night. They were completely hopeless at organising themselves, remembering stuff, you name it.
Neither of them could tie their laces until the were about 16, nor fasten buttons. They were dry during the day before they were 10 and at night by about 11. They have finally stopped walking into things all the time and can mostly be relied upon to dress themselves, although DS2 often forgets to take his pyjamas off first and their clothes are not always weather/occasion appropriate.
A diagnosis will make virtually no difference to your son's schooling, except in the way his teacher has told you. BUT you need to get one so that you have a leg to stand on with secondary transition.
My eldest went to secondary school (DS2 is HE.)After much fighting he was given transport, someone to help him find his way about the school, a scribe and a few small bits of support. We needed a lot of support from the primary head teacher to get anything at all for him and his entire secondary career felt like one long battle with the school to make sure that they did even a small part of what they said that they would. My DS2 got no support from primary school at transition, so the secondary would give him no help at all, even though he is more badly affected than DS1. That's why we HE him.
DS1 is now in his 3rd year at St. Andrew's and, obviously, living away from home. He is not only surviving but thriving on the independence. Neither DH nor I can believe it. He still needs reminded to cut his hair/shave etc. and he is still a scruffy beggar with odd socks, wrinkled clothes and mismatched colours, But he is fine because he now realises his strengths and weaknesses and knows what to expect of himself so he has developed coping strategies.
DS2 is going to college after the summer, providing we can get an appropriate support package. In the last year he has improved vastly as well. He actually manages to ask for his own bus ticket, occasionally, now, and never forgets to clean his teeth. Other things are taking a bit longer, but that's what we expected.
My DS3 does have learning difficulties as well as planning and organisational problems. WHen he was 11, he had a reading age of 6 and a writing age of 4. He was also almost completely innumerate, baffled by more than very simple sums and unsure even of basic number bonds. Now he is almost 14 and HE. He is still behind in MAths (although MUCH improved) and writing (I have almost given up hope, although he has improved to the point where you can read perhaps one word in 10) but his reading is now ahead of his peers, his concentration and ability to follow instructions is unrecognisable. He can even ride a bike and tie his laces unaided.
The only thing I can tell you is that things do improve with time. Even a small victory is a still a victory. Try not too worry too much or it passes on to your child and just stresses them out even more.
I don't know how the system works in Wales, but you need to be on the school's case. He should never have been allowed to walk about without shoes on! (mine used to regularly have them on the wrong feet, with their jackets on upside down, under their jumpers.)
You need to push for a support package even without a diagnosis and then be on the case to make sure that it is being implemented. The school should start dealing with his transition to secondary at the start of his last year in primary, so that the appropriate arrangements are in place.
If I can help you at all, just let me know. I know how difficult it can be.