Riven I realise that this is disapointing to you but honestly yyou need to realise that you havent 'failed'
I read the other threads where you were contemplating whether or not it was sensible for you to fast, now you have a conclusive answer
I havent fasted much in the past four years, as had a pg yr, a bfing yr, a pg yr, a bfing yr iyswim. I did a few days in the bfing years but really struggled but there is no way i could have done the full month. I was honestly dreading this Ramadhan, as i converted 7 yrs ago now so have never fasted such long days in my life and am out of practice. Alhamdillilah i am finding this year do-able, unlike the odd days i did last year i can fast without feeling unwell. This is because my body is ready to fast and the fasting is benefiting me.
Inshallah there will be a year in the futuire when you are well enough to fast, but this year just remember that Allah (swt) never burdens you with more than you can manage, i think that nobody would argue that you have plenty on your plate, just view these trials in your life (your MS etc) as your current tests and allow yourself to concentrate on those.
There are many other aspects to Ramadhan and so you dont feel left out just make sure you are fufilling those other obligations (charity/salat). Laytul-Qadr can be special, maybe you could find some time to read Qu'ran this month?
And make sure you have a happy Eid
Btw do you know about the new muslim project they will send you newsletters and might be helpful to you?