hellobello, i am sorry you are having such a shit time just now. It is funny how life seems to just throw all the shit at you in one go, thats how it seems to go for some reason.
My father had dementia and it is shit, there is no nice way to put it im afraid. There are drugs out there that can slow the disease progress down, irrespective of the cause, they tend to label these things but actually things like alzheimers can only be properly diagnosed post mortem, and by that time, whats the point? You have to be pushy with social services etc, but do try and get your mum a care team established, be that a social worker (fecking useless in my opinion but they have to be involved)or CPN. That way she has a professional to fight her corner. Maybe some respite care is in order. Practical things you can do for mum are things like, making sure the clocks are always right, only have one clock etc. Have an obvious calender saying what day it is, simple things like that. We used to put my dads name and address on several bits of paper and put them in his wallet and pockets in case he took himself off and couldn't get back home. If you contact the alzheimers society they can give you lots of practical information and also will fight your corner re care homes etc, if and when it comes to that. Age concern can help to. My Dads cpn organised for him to go to dare care, he loved this, and used to think it was his "job", bless him. It broke my heart to see him deteriorate, he used to need my DP to walk him home because he couldnt find his way - he lived in the next road! Im sorry, this is not very positive, but i strongly believe that forwarned is forarmed and you are in a good position now to make some positive contributions to your mum, if you feel up to it.
As for the rest of your family, do you really need their shit? If they can't get themselves together is it really your fault? It is a shame about the baby, but it is not your fault and it wont adversely affect the baby if you dont see him. I think you should tell your brother that unless he sorts himself out, you will not break contact but you will not be available to help him until he helps himself.
Bless you, you have been through so much, i dont know how you are managing, but you ARE, and you also took the time to post on my thread to support me, that was very much appreciated. I am having a better day today.
Please go to the doctors, you cannot expect these feelings to go away by themselves, as my doctor said, you woudlnt leave a back ache untreated, so don't leave depression/anxiety as it will only get worse. My ADs just take the edge of things and i can cope with the day, sometimes i have bad days, sometimes i have fucking awful days, but i manage, thankfully, lately i also have good days, and sometimes even really good days. lol - i almost feel normal
Hang in there, use this board as a sounding box and put yourself first, you deserve it.