I was just told that my heart is enlarged. How will this inpact my life expectancy?

I have chronic health issues. No stomach from car accident, fibromyalgia, chronic pyleonephritis, chronic asthma, Chronic pain from multiple scare tissues in abdomen. Chronic GI bleeder. Chronic infections. Escemic brain disease, begin brain tumor in brain stem (that sounds worse than it is). I am always sick. My doctor says my heart is getting enlarged because of all the hard work it does to just keep me alive. I am not ready to give up and die. I am spunkier, but this has me scared. I have just started to accumulate fluid in my feet and legs and hands. SOS