Stomach issues?

This is probably full of TMIs, you've been warned. Not sure of the policy for these things here, I'll delete if there's a problem with it.

I've been working on losing weight, and since I was getting close to my goal a little over a month ago I decided to start working out. Surprisingly, now that I'm no longer obese/overweight I rather enjoy it, and I've been doing c25k alternating it with the bwf recommended routine, total 6 days a week. On Sundays I go out with the bike. It's been a big change.

My weight loss has slowed down a lot/stalled completely, which yeah I can blame on increased appetite thanks to workouts, I've just recently gotten back on track. I'd love to blame water weight, but it's been three weeks and I have no excuse. I even put on a couple of pounds back.

However I've been having other problems to adapt. I spent the first couple of weeks dehydrated until I figured out how much I should be drinking, for starters. Currently I'm struggling with two things: hardcore constipation and stomach gases (I warned you).

I go to the toilet once every 2-4 days, when before I used to go every day. Drinking more and eating fiber hasn't helped noticeably. For gases, I just fart way too often and they stink like never before. Eating differently hasn't helped much.

Am I doing something wrong? Is my body adapting and will go back to normal in the future? Or is this what it is like, forever?