Need help with this please

Hello guys, my name is Nikolay and I'm from Eastern Europe, and I'll try to explain you my problem and hopefully find a solution for it.

I never had any problems with my Stomach, occasional diarrhea and stomach pains weren't common at all, maybe once a month or something, so I was always happy with it and never even paid attention to it.Soon after I turned 14sh, I started to encounter a huge problem with my stomach and my digesting. From that point to my life started to become a huge Roller coaster of emotions and huge level of depression. My whole life started to orbit around my stomach, most of my thoughts were if I was going to get diarrhea or when & how I emptied my bowels. It came to that point that I was too afraid to even go to my highschool which resulted in bad grades, but somehow I overcame that problem and managed to finish my school, had a lot of problems but I could simply cheat with a simple paper from my doctor that I was sick, and they bought it. My social life went totally numb, I rarely socialized outside of my Home, and even on very rare occasions, when I was 'forced'' to go out, I would do my research about the nearest toilets around that place and how much would it take me to take a cab, and ride home in case of an 'emergency''. As I said, this problem ruined all my chances of a stable life, most of my weekends, are watching tv-series and chatting via social medias. When I started going to the college (around 3 years ago), during the first year I had no problems with attending it, I still had diarrhea, but never really cared about it, and my stomach problems were reduced for some extremely peculiar reason, I never cared about it, and my first year went extremely good, so good actually,that I forgot about all those awkward situations I was put during my highschool years, I started to socialize, my life got a lot better etc, you get my point. But at start of my second year at the college, the problems came back for some strange reason, and are still going on (I just started my third year at the college). And everything is bad as it were a simple timetravel to my highschool days, I have severe depression the reason being my constant fear of diarrhea, diarrhea itself, and bloating. I started to eat less, lost a lot of weight and rarely go out, almost never, and even when I go out, I always have to have some backup plan in case my stomach wants to co*kblock me again. I really don't know what to do, its becoming an extreme problem, in a year or two I will become a teacher at some school and I cannot simply cancel my classes and such.It started to mess up with my mental health to that point that even a single bowel movement would be indicated as a diarrhea and my panic attack start to happen. Any insight is HUGELY welcomed, thanks in advance

PS: I never consulted my doctor for some reason,nor I even know if this is just IBS, or some other, more serious problem

Thanks for the reply sir, will do