Post natal depression

I've been diagnosed with post natal depression, this is my first baby and she's 10 days old. I'm already on anti depressants and have been for years. I'm not shocked by it, I knew it was coming. Just a lot of crying from my end and feeling overwhelmed and hopeless. I just wanted to hear some stories from ladies who have experienced this but have come put the other side. How long did it take to feel better? I know it'll be different for everyone but it'll be nice to have an idea. Thanks!