You really need to actively choose your source of happiness, every single day. In my case, one day every week it's my regular electrolysis visit (my electrologist is an absolute sweetheart of a lady), every other week it's my therapist's session. All the other days, it's twice, when I put estradiol tablets beneath my tongue in the morning and evening.
Some of the more significant events that should thrill you when they happen:
a) noticing your urine no longer smells so strong in the morning
b) noticing your sweat no longer smells so strong at all, anymore
c) when little hard lumps form behind your nipples
d) when those lumps form into tiny mounds
e) when you no longer wake up with morning erections
There's a few more, I just can't think of them, right now.