SDP, child at university, sole occupancy

Hi all, I need some help.
I’m recently in receipt of ESA income related support group and I have been receiving it for for 6 years now. Last November I applied for PIP and in April this year after the assessment I was awarded the Daily Living component (less than two weeks after telephone assessment). I was send a form for SDP which I filled it in and sent it back. It’s taken this long to get an answer from DWP and today it was finally approved.
I live on my own, family lives quite from me and my only child started university last year in September and has been living in student halls. My son has signed a tenancy agreement for 52 weeks, and has paid the deposit and few days ago received the key and paid this month’s rent. He will be continuing his studies for the next three years, full time and his university is over 185 miles away from my home.
On one of my phone calls with ESA was told the reason SDP it’s taken so long is they needed more info with regards to me living alone, a letter sent to me never arrived but I explained my current situation and if they needed the tenancy agreement that my son had just signed at the time. I was told that the council tax bill showing “single occupancy” would suffice. They received that bill and called me today to say that it has been approved and they will start paying me Sdp.

Today I received a letter from the local council Re: Council Tax Support, writing that it was necessary to review my Council Tax Support entitlement because my child turned 20 in April this year.
They need to know if I receive any Child benefits and if not what date it stopped (April last year), University/Further Education (please provide the course enrolment letter), name of university, length of course, start and end date, where he will be living (halls of residence or private rented accommodation), will they still have a large portions of their belongings to my property and “ Do they intend to live in your property at the end of the academic year/course, or at least within 52 weeks of the course starting?”.
The rest of questions are about employment/apprenticeship and if my son has made a claim or received any benefits.

My understanding is that if he’s paying rent for the full year (52 weeks, even though studies are 40 weeks) and is studying full time, living away from home and only visiting on holidays ie Xmas for a week and a couple of weeks during summer, I still class as living on my own.

Also my son will be sharing his time during summer between me, his father and visiting friends (in other cities). All his belongings were bought to my place two weeks ago when the term ended and a good chunk of it were taken to the new place couple of days ago (couldn’t take it all as only a small car) when he got the keys for the new place. The rest will be taken soon when his dad will give him a lift (his dad needs to hire a bigger car in order to do so).

What is my situation, do I say that he will be living with me during summer? Even though that time will be split between myself and his father and also staying with friends?

And to make things more complicated he’s thinking of getting a few hours summer job to pay the rent for the flat he’ll stay whilst at uni.

Sorry, this is so long and confusing, but I want up do this right and I can’t afford any mistakes.

This isn’t legal advice, but your son’s main residence is at University as he pays rent there 52 weeks of the year. He can sleep where he wants surely? Visiting his parents is permitted.
If you want ‘legal’ clarification I would phone the Shelter helpline. This will put your mind at rest.