It is incredibly hard to looking after your LF on your own and being there for others @CheerBear and also look after yourself. It cannot be inderestimated how much mental power that all takes and adding in extra things such as this work you will be doing actually increasing that mental pressure even when it is something you want to do. You are certainly self aware enough to know that all of this is impacting you and therefore can do things to help yourself - and that is so important CB.
I hear you about wanting/needing to do more in your life - there are things that you can aim towards and work towards doing. I think this volunteering role is a great start in that direction and maybe that will give you a little more confidence to be able to go back and finish your degree. I do hear you about 'life' walls though - they do seem to get in the way of what we want to do and what we ultimately can do - that is very frustrating.
I do think you have come a long way with what you can and do deal with in your life CB so maybe the next big step for you is just around the corner - and I believe that you will approach whatever that is with an increased level of thought and confidence because you have so much going for you and so much to give Hon.