Hello Surfie, depression can affect all walks of life and very sorry it's been 20 years for yourself and suggest that your doctor needs to review your medication and suggest that you try something else or alter the dosage, because our body changes as we get older, and what may have benefited you years ago, may not be doing the same now.
If you feel as though you need another opinion then try another doctor who may have a different attitude to the medication you are taking, plus they could suggest speaking to a psychologist by using a mental health plan, which entitles you to 10 Medicare paid sessions per annum.
Please don't take your age as a set back, because I'm also old and only want to help you.
Take care.
Geoff.
