There is no accept button because I haven't answered your question yet.
Yes, I truly believe it is IBS. Possibly you may have some lactose intolerance - try to pay attention to see if dairy products make your symptoms worse. You may not notice right away but just try to pay attention to that. If you don't see any difference in your symptoms when you have dairy, try to have gluten free diet. You can google "gluten free diet" and you will have tons of information come up. Gluten is a protein which is found in many foods (mostly processed foods and in bread products). See if sticking to low-gluten or free gluten diet will make your symptoms better.
So, again, I do think you have IBS but since you don't want to go see your doctor, lets try lactose free diet for 2 weeks and if you still have symptoms, try gluten free diet.