Basically... should = good advice, or a soft suggestion. have to = someone else is telling you to do this. must = personal obligation. Sometimes this is used as a strong "have to". It's most obvious when you use the negative forms.

"I have to" and "I must" are the same, "I should," usually means it will be better if you do that thing, but it is not necessary. "I have to finish my homework." [Or else I would fail the course] "I must go to the doctor." [Or else I will stay very sick] "I should clean the dishes right now." [But I don't want to, and I could still go it later]

Thanksto everybody))

From my point of view, you have a choice to use anyone of it. Doubt? then you have to/ must/ should try.