No need to apologise, you're thoughts come through perfectly.
After experiencing years in depression up until some time ago, I've learned and are still learning many life skills. I never understood until recently just how many life skills are lacking in order for us to feel some flow in our life.
One of the greatest revelations for me comes down to the importance of raising our self through challenge and the importance of finding those around us who are enthusiastic and capable when it comes to helping raise us. Your brother sounds like he could be one of these people who enjoys lifting others.
I imagine you would have raised yourself to many challenges in the past, some small and some great. You accepted the challenges that school brings, the challenges that come with maintaining a social circle, the incredible challenges that come with caring for someone who is seriously ill and the overwhelming challenge of losing them. When you think about it, you have risen often and during those times would have experienced moments of great pride and genuine joy (during the happier times).
Personally, I can spend days trying to work out the huge challenge that can be draining me before I understand what I need to do to master it. Sometimes, I can pick a number of tiny achievable challenges to rise to which remind me of how capable I am, in so many ways. Perhaps your greatest challenge involves circulating again (discovering friendship groups). This can be a massive undertaking, without a doubt. Perhaps your brother can help you come up with a few ideas. Setting up a time to meet with him and get the ball rolling will also raise his attention to the help and care you need.
Afb, try writing a challenge list for the day and then try rising to as much as possible on it. Make it achievable and perhaps throw in one hard one. You could have 50 things on the list, from stretch and yawn for 10 minutes straight in the morning today (stress release) through to order a cup of coffee and say something to make the barista smile. It will be a simple yet very busy day. You'll be surprised what you're capable of. Give yourself flexibility; perhaps make 40 out of 50 the goal.
Those life skills I mentioned: One that is seriously lacking is 'How to consciously raise our self through challenge'. Beware, once you get the hang of this it can become a little addictive - you begin inviting challenge, so as to feel the high of rising and, above all else, self love.