I haven't received the support promised in my funding letter. What should I do? It has been 4 months that I have started my master's degree in North America. I got my funding letter from my supervisor when I was in my home country, in my letter it was written that I will be a fully funded student. Now I am here and he does not pay that amount money. even for my first semester, I paid all of my expenses and tuition fee from my pocket. I finished those amount of money that I brought from my home country. now my supervisor does not pay properly. Life became difficult for me, even the university restricted my access to add and drop due to the hold. I am a good student who cares about studying, I hate thinking about money and tuition fee. I am not the guy who can study and do research like this. My prof pays other classmates more than me. This situation really disappoints me and overwhelmingly hard for me. Several times my parents wanted to send money but I did not let them. (transferring money is difficult from my home country.)
I feel like crying these days and I could not stop it.
Do you have any recommendation or sample letter? how can I make him understand?

+edited: I tried to talk my classmates about this issue. But when I am explaining this issue to them they think that there is something wrong with me and my classmates do not offer any collaboration with me such as publishing something or studying together. This payment issue affected my self-confidence completely.
Based on a conversation in the comments, so you have basically no reason to see this as anything but a mistake. You were never told you would be paid anything less than you were offered. You have not communicated to anyone that you are being paid less than you are supposed to be paid. Most likely no one knows you are not being paid correctly.

You have done a very silly thing by letting this go on so long. Go talk to your advisor face to face as if your advisor is a normal human being, let them know you think there is a mistake because have not been paid the amount you expected to be paid, and ask who you need to talk to in order to get this fixed or whether you have misunderstood something. If you cannot meet face to face, you can say the same thing in an email.

There is no need for this to be damaging to your relationship, there is no need for you to accuse anyone of mistreating or abusing you, there is no broken relationship already. It sounds like there is an administrative error that needs to be corrected. Administration in a university is complicated and involves people that don't know you or your advisor personally at all, they may have nothing in their records to show what you should be paid. The likelihood of mistakes increases dramatically if you are supposed to be paid from more than one source.

Only if your advisor refuses to correct the mistake and refuses to let you know who you need to talk to to correct the mistake should you assume any malice.