You feel worse now because you've gotten to much good bacteria out. Maybe you didn't notice it before, but now it's catching up to you. When you don't have enough good bacteria the food you eat will get stuck to your colon walls.
I don't think probiotics work that well because it's impossible to replicate your own bacteria. You're definitely getting more backed up if you're doing Oxypowder and colonics and eating solid food. And a probiotic enema isn't going to help much because it only reaches the lower part of your colon, when you're flushing out you're whole colon.
The first couple times I did colonics I just ate solid right afterwards and I made it worse. Then the other times I did them I only drank juice for a day or so afterwards.