Dear Ella95~
Welcome here to the Support Forum. It's called Support becuse that is what people need -including you.
Reading your post I get a good idea of the very hard task you have taken on. A good relationship is a partnership, with each doing their best to look after the other -and being reliable -quite apart from the good feelings and fun of simply being together
At this stage it looks like you have had one month of that followed by 6 months of being a carer, as you BF is in no condition to navigate life well.
It is a huge strain to worry about him all the time, and another to have not walk on eggshells, plus not being able to be honest with him. Over time this can have a bad effect on a person, making them ill. It also makes for separation.
So you need support. Might I suggest firstly you see your GP and discuss the situation, that means not only will a medical eye be kept on your own condition but you might also gain some insights into what to expect and why things happen.
Secondly is there anyone personal, family or friend perhaps you can vent to, discuss matter frankly and simply be listened to with feelings of care? Trying to deal with all this yourself in isolation is so hard.
Congratulations on your new job, as an educator for 17 years I found it a most rewarding and enjoyable career, even if very hard at times.
One approach you might take is for your BF's medical regime to have an overhaul, it is only marginally effective at best at the moment, and there may well be room for improvement. Perhaps you might gain his consent to accompany him and (gently) give an account of how things are.
As for being selfish -nonsense. Your desire for equality, engaging in normal activities and feeling cared for by someone who is on your level are perfectly normal healthy desires.
You are always welcome here, and if you would like to respond to the above that would be great.
Croix