I am so heart broken on the fact that whenever I plan to go on ziyraat my exams always come up as a hinderence between the dates. Is it possible that I am sinning in a way which is not letting me go? Sometimes people often say that ‘You’ll go when you’re being called’ (jab bulawa hoga tab jaogi) and as beautiful as it is, I also felt that maybe mola doesn’t want me there.
Please suggest something that I can do to help myself in this regard

You are trying your best to go for Ziyarah and it's not because you are sinning that you can't go. Maybe you need to plan in such a way that your exams are not on the way. Best wishes. pray to Allah inshaAllah He will soon make it to reality for you to go. Allah is so Merciful and we need to believe in His mercy and His love. Please never think negative of our grand masters