Hi @Scarlett-W
Hello and welcome.
I’m a little later than normal to the thread for my own health reasons
Emerald has covered off the main things and the other words you have had will I hope be some reassurance 
I hope that 40 things Emerald referred you too will give you some insights such as the fatigue triggering that is anything blue light like phones tablets and televisions - also healing in the head uses a lot of energy internally and it isn’t available for use externally - rest is important
I wanted to add or emphasise a few points.
While no one would ever wish it upon you as an opportunity The experience you’re getting by being a carer will be invaluable throughout life forever.
Its Very much more relevant & useful and a preparation for the rest of your life in every way way better than a year at university - That is provided You keep an exit route to a life after the acute needs for caring settle-down.
The short-term adjustment and pressures maybe very very hard. It’s vital you and your mum have some escape valves and respite
Especially as the council social services will be very keen to leave any solution up to you rather than allocating resources. You must find avenues by which you can take a break and have some peer support and advice to show you you’re not alone and help you navigate the families new dimension to everyday living
others have suggested groups although the two mostly useful links are
Https://www.stroke.org.uk/stroke/support/groups/map-local
Https://differentstrokes.co.uk/all-groups/
And also
Maybe Contact us - Citizens Advice and ageUk to
Also have a look at Extra help and concessions
I don’t have the spoons to signpost more but there is much more here discoverable by searching
Caio
Simon