This is a perfect cumulative escalating storm as this current dynamic has you feeling "miserable, snappy, on edge, under pressure" which she senses and therefore feels more insecure of her attachment to you - so she ups the ante od trying to attach to you - but you just become more resentful and the cycle spirals.
Communication, boundaries, reassurance and consequences are important here. You seem to be poor at implementing all of the above and are inadvertently making her more anxious/dependent and craeting a rod for your own back.
She needs to experience managing her own entertainment and social life - so that she becomes proficient and confident at it. She will need some support and guidance from you to be able to achieve this. If there is an undiagnosed ND then consider that socially she is maybe 4 years 'behind' but keep nudging her to independence. I would agreed with others what is she doing socially at college M-F? Are there home friends/old school friends around that she could be encouraged to reconnect with? She is also being very impulsive and demanding and you are responding in a very reactive and impulsive way as well.
She needs to learn that these are inappropriate behaviours for her future relationships and friendships:
Follows me around the house - communicate that this is uncomfortable for you, tell her to stop and that you will come to speak to her in an hour.
as soon as she wakes up messages me asking what am i doing - communicate that you will be turning your phone off at night and tell her to stop. Tell her you can share plans over breakfast at 10am.
when i go to a friend or my mother for a coffee she is constantly messaging me asking when i am home - communicate that you will be turning your phone off when out and tell her to stop. Tell her you will be home by 2am.
says 'entertain me' a lot - create a boundary - say you will spend Sunday mornings together (for instance) and alternate weeks each of you chooses the no cost activity.
seems to want to hang around me all the time, i want some time but not 24 7! - as above
has friends but rarely sees them - communicate - explore this with her and encourage her to make plans / get involved with them.
wants me and her to go to all these places for lunch and shopping and its really nice but im struggling to afford it every week a nd my savings now v low - communicate and create a boundary - say you will spend Sunday mornings together (for instance) and alternate weeks each of you chooses the no cost activity. Encourage her to get a job. Tell her she is an adult and can now pay for her own treats.