Looks as if your poor neighbour is becoming increasingly needy and compulsive in her behaviour. She clearly needs to be needed but she doesn't respect boundaries and although she hears what you say, she doesn't actually listen....or remember. It's doubtful, therefore, that any conversation with you attempting to explain how this is affecting and causing you problems is going to get you anywhere. She won't be interested, focussed, it'll be immediately forgotten.
You don't say what sort of age she is - younger than you? But she's obviously strong enough to involve herself in 'doing good deeds' all over the place. Sadly, she's not picking up on the fact that recipients should have a choice! And at the moment, you're 'it' - the target for good works and visits which maybe give her purpose and make her feel a bit better about her own life.
Don't waste a minute thinking you're mean or need to be nicer. Apart from the fact that this Forum will show you couldn't be much nicer or kinder or more patient and sympathetic, your neighbour's attitude towards you seems to be based more on her own needs to fulfil some role in life - never mind what you say or feel.
Rather than contact Adult Social Care or her Surgery with concerns you might have about her, and since you have spoken to her family it's possibly time to let them know how you are being impacted by her behaviour. Tell them, personally or in a letter, that you are concerned about her and the fact that she is obsessed with being in your life day on day and relentlessly, whatever you say. This is not a complaint, tell them, but you feel they need to know so that at least when she starts complaining about you and your 'absence' they'll know the facts and can keep reminding her that you do have your own life and responsibilities and friends etc., and you need time and peace now to live your life as you choose. It's nothing personal, tell them, you are just struggling to deal with something that has become overwhelming. Over to them, basically!
Plan your retreat from the trap that you find yourself in by keeping your door locked, windows covered, all the things which make it too easy to monitor your comings and goings or just to walk in when they choose. Become inaccessible - at least until she moves on to someone or something else. You don't need to be any nicer than you are! (Many on this Forum will know this!) Just make the neighbour's behaviour more difficult to experience up close and personal. Don't be sad, you're doing nothing wrong and make sure you hold on to your sense of humour and determination. You can succeed with this, I think, but not by trying to change your neighbour.
Stay strong - wishing you the best of luck with this.