I'd chalk up such short term memory issues to anxiety, restless thoughts, and not being focussed.
What helps me get over this is: not to worry about it (accept that it's normal just now, else worrying about it will worsen the symptom for me), and try to fill my days with low stress activities that keep me occupied and healthy. (I do lots of walking when I'm up for it.) I also watch my diet (sweets and low fiber carbs will send my blood sugar levels roller coasting somewhat, the resulting increased anxiety levels make remembering things in a timely fashion all the more challenging).
Knowing my memory's unreliable, I rely more on writing things down and using 'alarms' for appointments (my newish cellphone has an excellent alarm function: you can program up to a half dozen event reminders in it, as one-time alarms or recurring on that day(s) of the week / time).
Don