Really hope someone can help. My DS (now 11.5yrs) was screened in school at 8yrs and showed clear dyslexic tendencies. He was advanced in some areas - 90th centile for some aspects including cave and mobile (equivalent of an 11-12 yr old at 8 yrs old) and below 10th centile for reading writing and spelling. He was put on an IEP and support put in place and he progressed well.
He was then taken off the SEN list last year but has recently been put back on following my insistence at another screening test to see how far he's come. It's showed he is still advanced in some areas, and although the gap has closed a bit, but at 11.5 yrs he has the reading, spelling and writing ability of an 8-9 year old
.
I really want a formal diagnosis (supported by GP as his self esteem is suffering) and to explore whether he should have extra time in SATs.
Can anyone please help me get up to speed on what I can do to make sure he's getting the right support through SATs and transition to secondary?
Ideally I'd like him to have a proper assessment so we know exactly what we're dealing with, and this would be supported by my GP as his self esteem is affected by thinking he's stupid compared to everyone else, and he is so not! (He does not hear anything negative from anyone else, but he is very aware of his differences to his peers, and especially now his younger sibling is overtaking him) so it's all coming from within, which is heartbreaking).
The Senco has said it would be unheard of to have him assessed by the local authority for dyslexia, and very hard to get extra time in exams, since the parameters have changed recently. I am not in a good position financially to be able to do an assessment independently, and feel like I'm floundering at finding the right information to ensure he gets all the support he needs to reach his potential. 
Grateful for any advice 