Sorry to hear you're still struggling with bloating and stomach upset. I would think that any time now your bloating ought to settle down a bit. I would suggest that you be extra careful to eat easily digested, bland, smooth foods. No fun, I know, and when you're having trouble with even those, the temptation, I'm sure, is to eat something you'll enjoy more. If you feel like it doesn't make any difference, why not? I get that.
Still, if you consistently baby that stomach of yours for an extended period of time, it might just help settle things down more quickly.
You're one of those who needs to be reminded of the 6 month to 1 year healing time frame. Believe me, I understand your fear that you will be like this FOREVER, and it's a frightening thought.
Yes, you'll likely have some quirks forever, but this extreme a problem is a healing issue and it will resolve over time. I wish I could put you in a time machine and you'd come out completely healed, but unfortunately, that's not how it works. You have to slog along through this rough time and just go with the flow. (Even though the flow isn't cooperating!)
Yes, your stomach is very likely worse than it was pre-Nissen. It has been assaulted with surgical tools, stretched, wrapped, and stitched. The vagus nerve has been irriated as the hernia repair and Nissen were completed. Your upper GI tract has been through a major revision. On top of that, your stomach and esophagus were likely already quite irritated because of the pre-op issues that brought you to surgery.
I can hear from your post that you're getting to the end of your rope. I suggest that you move back toward the middle of that rope, and take a very deep breath. It's no fun to suffer through this recovery, and you're obviously one who is dealing with more bloating than average. However, stressing over it will only add to the problem. I think all of who suffered with GERD issues know how stres can make it worse. In that same way, your emotional stress can add to your stomach's physical stress!
Feeling everything move through the digestive tract is very normal through the healing stages. I remember hearing and feeling the stomach depositing things into the small intestine. It's a strange sensation, indeed.
Three and a half months is moving along. I understand why you're impatient to get on with your normal eating life. Still everyone's body reacts differently to this surgery, and while some don't seem to deal with as many issues, there's no way to control how your body will react to the surgeon's assault on your innards!
I'm sorry I'm not much help here. Still, I'm glad you're posting, so you're not dealing with this alone. I expect others will be by to post as well.
I hope things feel better very soon.