When I saw the title of this post, I thought it was not going to be what it sounds like, but reading story makes me feel sad. I can relate a bit as the only son of 7 children born to my parents - except that my parents are still alive. But am still the financial burden bearer. But then, your looks worse with no parents and a sick brother.
My advice is - Trust in God. Because you need divine help to be able to bear everything. I read the bible sometimes and this scripture comes to mind when I feel weak and small and loaded down:
If you trust in God, he will give you the strength to soar on wings like eagles.
I really do not want you to quit Hive because I believe you can have the mental strength to overcome all challenges. Instead of quitting completely, maybe you can reduce the workload here to something manageable based on your prevailing circumstances. Then when things balance a little, you pick up.
Am really sorry bro. Life in this world can be hard.