Greetings . Well it seems like your sleep-wake cycle has got disturbed which is leading to this sort of odd sleeping pattern that is affecting your quality of life and causing some physical symptoms like stomach ache. This can be managed by adhering to and practicing proper sleep hygiene and taking a sleep aid drug at night so that till morning you can get a refreshing uninterrupted sleep which shall correct this sleep-wake cycle disturbance. You shall ask your family doctor to place you on a sleep aid drug called as zopidem at dose of 5mg to be taken at night half to one hour before sleep for at least 2 weeks which will bring back the normal sleep pattern . Alongside use of this drug you shall practice below mentioned sleep hygiene. 1) fix a time for sleep and waking up and rigorously adhere to that to establish discipline. 2) wear loose clothes , sleep in a well ventilated room which is dimly lighted. 3) Avoid heavy meals and coffee or aerated drinks at night. 4) Avoid watching television or listening to music late at night instead read a book or novel if not getting sleep at the desired time. 5) Do regular exercises and yoga along with maintenance of a healthy diet schedule. 6) change your sleeping room or bed for a few days so as to try a new environment for sleeping which can re-establish sleep at the desired time. 7) Avoid taking alcoholic beverages at night time. So you shall apply this sleep hygiene in combination with zolpidem and hopefully this will take care of your underlying problem.As soon your normal sleep returns your stomach condition shall improve. I hope this helps. Wish you all the best. Regards