I have seen your other thread - starting two threads in different places and not linking them is not helpful, espcially since the two issues are effectively one.
I haven't entirely understood everything here as it's a bit hard to read / follow. But it seems that you have had a lot of absences and are also going off in the middle of the day to do a school run when you are supposed to be working. Whatever the rights and wrong of what is happening with the detail of the sickness absence, you are doing yourself no favours here. Work is not something that you fit around your personal life, and you most certainly do not tell your manager that they should not schedule meetings with you at certain times during the working day because you are going out to do the school pick up!
And you really are then skating on exceedingly thin ice to tell the employer that you need to do a school pick up during the working day to support your mental health because working from home is making you too isolated. Because I would have to say that my first response to that as a manager would be to return you to the office.
I am sorry about your miscarriage, but that is all a bit miseleading as it doesn't have anything to do with this current situation. As far as absence management goes, the employer will have a policy and that policy should be followed. I don't know what your policy actually says, but if you were off sick between the 9th and 20th November, that length of absence alone would trigger a first stage with my employer, so it is entirely possible that you are in your employers first stage since you also had at least one further sickness absence in the last year. To determine that, you need to check the policy.
It is normal practice that you would then be set targets which you are expected not to exceed in terms of the number of days off sick, and it sounds like that has been done. No more than two more absences would also be a reasonable and common target - there is usually a total number of days as well, but that depends on your policy.
So I am honestly not seeing anything much wrong here. I can't see your policy so obviously it depends on what it actually says.
Quite seperately from that, if you are supposed to be in work during certain hours, then you must be in work and not going off to do the school run. Your work is the priority during working hours, and you must not tell your employer that you won't be available because you have other stuff to do. You may ask for some flexibility, but in all honesty, now would probably not be the time to be asking for too much. From the employers point of view your attendance is unreliable on more than one front, and you may be heading for disciplinary action that could result in your dismissal. You should bear in mind also that questions may be raised about who is looking after the children when you get back from the school run. Because in many workplaces you are not allowed to be providing childcare during working hours, and if you are picking up your children from school, then who is then looking after them?