Not really a reply to your post, but people can get too concerned about happiness, eg. if they're not, there's something wrong. I jumped up and down like a yoyo when I was younger from suicidal to ecstatic, most of the time being mildly miserable. After a while I was able to remind myself that being mildly miserable wasn't too bad, even when I was going through ecstatic or suicidal episodes. I've happily remained mildly miserable for about the last 20 years.
Your medical stuff is obviously on a different level, I assume they've found a low cell count in your blood, both white and red? It's just that my mother got that diagnosis a few weeks ago and they put her on an iron drip that's supposed to last 6 weeks, but she goes white faced and weak every time she stands up, and I'm wondering if they gave you a way of testing how you are? The hospital decided she was too old (94) to risk invasive methods to find out what was causing it, (rectal tumours was a theory). She's also got heart trouble which at 94 is probably normal, but her sister is 107 and we're going for the record here! Sorry to link this to your situation at 38, it's a totally .different scenario