I'm not sure what you want from your posts.
There isn't a magic wand to wave or a set of words that will make the problems disappear.
I really don't understand why you think dismissing your DS expressed concerns will magically improve his confidence.
I've had one child say reading wasn't for them and one child say they were no good at maths. I found out why - in both cases they were shaky with the foundations and had adults round them saying their sex didn't do those activities.
So for maths I found a on-line site - mathsfactor with a female fronting it. They went over basics did loads of practice past tests before moving on and saw a woman being good at maths. It took time many months before confidence developed and then it took that school few years to realise how good they had gotten.
They didn't need me to tell them they were good they know it.
Time before they got the confidence I emphasises that like all things in life practise was the key and made them work at it every day.
Same with reading - checked out hearing and eyes then went back phonics basis which were lacking - dancing bears book A or B or fast track A/B might be applicable for your DS and again practise the shit out of decoding.
In mean time I also pointed out male relatives reading, found male writers and found audio books with male readers and sometimes the same as the writers to listen to. I also did graphic novels and non -fiction books to try and keep up interest.
Once my Ds had a though grasp of the basics I couldn't have stopped him reading. Again I didn't need to tell him reading was for him or he could do it I empowered him by giving him the skills to do it.
I'd also consider what he is currently reading - is it too hard, too easy, too boring all of which would help put your DS off reading.
If decoding is fine then see if it's reading comprehension that is the problem - reading with them making sure they understand the vocabulary and can find relevant information from what they have read.
You've chose the option of a maths tutor - I'd keep going with that and give it time. Time to fill in the bits your DS struggles with and once that is done time to develop confidence.
TBh I'd let the school get on with what they are doing and if they say he is too dependent on TA help ask them how they planing to overcome that.
In meantime continue to build the skills at home.