When do I need to worry about constipation?

My IBS was predominately IBS-D/loose stools. It gave me anxiety about going in public and using public restrooms, and I started to over use Imodium. I took a couple weeks off of off but took 2 before a 10 hour flight for vacation even though I didn’t need them. Well fast forward and I couldn’t use the bathroom for at least 4 days. When I finally could I would only go a few rabbit pellets 2-3 times a day. On tge 10th day, I get home and I think I go a semi normal amount, but still a bunch of rabbit pellets. Then the next couple of days, same thing only a very small amount. Two days later I feel like I go a “normal” amount but STILL little hard masses. Now my anxiety is about constipation, not diarrhea. I’m worried I’m going to get a bowel obstruction, or vomit up feces (I read this online could happen?!) or it is going to cause me to get overwhelmed down there and cause incontenance. Should I go to the hospital? I also am pretty thin and under eat but still.