I’ve known people given 0 points on their PIP assessment then given high rate for both on appeal.
obviously it doesn’t mean you will, but if you feel they got your point score wrong you have to firstly have a Mandatory reconsideration.
To do this properly you need to ask for the full assessors report ( not the award letter) you can ring them and they will post it.
look on the CAB website for samples of MR’s
Also they tell you you only have 28 days to respond, but ask for more time if you genuinely need it.
If you have no joy then an appeal is your next step.
bear in mind though sometimes they can also look at it again and give you less points, but that is rare.
Unless your condition has greatly improved I would get as much medical evidence together as you can and go all the way to appeal, you really have nothing to loose.