I'm sorry to hear about your Dad liveandlearn, that sounds horrible. I've used drugs/alcohol to escape feelings and emotions to. Now that I'm sober and have to sit with them, I've found that being a part of AA or NA is a huge help because of the 12 steps and the fellowship. I can talk face to face with other addicts about the struggles of sobriety. SR helps too, but it's never kept me sober.
To answer your question. It took 2-3 weeks to feel like myself again. That first week sucked a lot, but it gets easier and easier so keep moving forward. I remember that first week feeling like the WD was never going to end, and that I would never be happy again. It's simply not true. My first week I was tired, unmotivated, unable to sleep, or sleeping all the time, depressed. Oh and the cravings! You've made it through the worst though, and it should get A LOT better real soon! Don't hit the reset button, Day 1 of beginning an opiate detox is hell.