Question: Severe bloating - 8 months of MISERY

Hi, these last 8 months have been the worst of my life. 8 months ago i accidentally overdosed on celexa for 2 weeks straight, and since then my quality of life has plummeted. I've been medication free for months and months now, but my symptoms persist..

DAILY: severe bloating/distension, muscle twitching DAILY/WEEKLY: joint pain, chills, acid reflux, upset stomach/abdominal pain, dizziness, drowsiness, appetite loss, burning stomach ....

I can accept and handle the other symptoms, but the bloating/distension is absolutely too much for me to enjoy life. Some things of note:
-I get a large, easy to pass bowel movement every day at the same time
-Bowel movements do not relieve any of the bloating or discomfort
-Only flatulence (highly infrequent) has shown to give (small amounts of very temporary) relief
-The bloating/distension has not returned to normal (or close to normal) for a single moment in 8 months - It is generally very bad when I wake up in the morning, and gets worse with each meal - Most of the time, it is unbearably uncomfortable to stand or sit upright – Sometimes lying down brings a bit of relief from the pressure...
Basically, I'm stuck in bed all day, every day..
Trying a lactose/gluten free diet had no effect.. probiotics didn't seem to do anything..

I'm assuming it's not IBS because I have no trouble with bowel movements.. I've been reading about SIBO.. but SIBO seems to come with diarrhea or constipation.. I've had tons of clean blood/stool tests, looking for everything from lyme disease to parasites.. I get my scopes done in a week.. I'm going to try and get hydrogen breath testing and intestinal permeability testing.. But I have no idea what to do.. Is there a possibility antibiotics could clear up the problem? I'm very scared, I'm 24 years old and having my intestines feel like they're going to burst 24 hours a day is not something I'm willing to deal with long term. Please Help me!!! Thanks so much