Why am I still here

Having been living with heart failure for 3 years now above everything else I sometimes wonder why am I even still alive. I'm really trying to be ok and be the calm within the storm or whatever and in fact I had a very positive experience yesterday with a new friend and I'm excited to type about it.

Why I'm venting about this now though is that my body has upset me once yesterday and again today. Not sure what's going on but my energy levels are so low. Instead of my energy lasting 3-4 hours it literally lasts for 45 minutes tops. I didn't even do a lot of things just a walk and had ice cream and suddenly I feel fatigued and my heart is racing and that I need to lie down asap. Could be the heat or vitamins defiency I don't know yet and it could be my fault having been ignoring my supplements lately.