It's not hospitalization level depression, more like therapy level depression. Fortunately it hasn't been bad enough where I had to go to the hospital. I have gone to therapy to try to do it without meds, but the problem is that I go to therapy, try to come up with coping mechanics, stop going to therapy and then relapse, and the cycle's gone like that.
With your backstory I certainly can understand why you don't want to try out drugs. For many therapy will be enough to get back to were we belong, and for many it won't. That's however up to you and your therapist to decide.
I can try to explain why antidepressiva doesn't work like painkillers/opiodes. Hopefully I'll make it understandable, but I'm not the best at these kind of things.
Let's say your body normally has 10 "painkilling molecules." Now if you are hurting severly you might need more than that to make the pain more acceptable. So you take painkillers that give you another 5 of these molecules, to a total of 15 in your body. Now if you do this for a long time, and overdo it, what happens is that the body says "hey, it's only supposed to be 10 of those, why is there always 15? Maybe if I lower my share to 8, it will be better". So now with the same dose, you have 8+5=13. Now that's not enough to kill the pain, so you increase the dose to 7 for a total of 15. And then the body lowers from 8 to 6 and you increase the dose and so on.
Now if the doctor handles this properly this shouldn't happen of course. Sadly it seems like your dad wasn't taken care of to the extent that he needed and deserved.
Antidepressiva work differently. Now normaly say we have 10 "happy molecules" in the body. If you are depressed this level is lowered, so your body releases less of these. Maybe 8. Now what antidepressiva does is that it raises it back from 8 to 10. It does not however increase it over the normal body amount. Now if you recover from the depression your body itself will start making 10 of these. If you continue on the medication you will however not reach 11 or 12, but you will stay on 10. Seing as you never go above what's normal the body won't start to lower it's own production, so when you stop taking the meds you won't miss them.
I hope that was understandable, and I hope it helps you. Medication is certainly not always the answer, and it might very well not be the answer here as well.