The letter would depend on several factors. Like the previous writer stated, your age would be an important factor. How old you were would impact you recollections of the event. Young children would most likely not remember much of the Great Depression.
If you were of working age, your profession would impact your letter as well. Farmers were impacted as prices fell. This would impact their earnings and the amount of work they needed to do in order to make a profit. The need for government handouts and charity was large.
Families had to learn to make good with what they had. That is how depression style cooking came into being. Many recipes from that time do not utilize flour or sugar.
Many people lost their homes because they couldn't pay their mortgages.
"Shanty towns constructed of packing crates, abandoned cars and other cast off scraps sprung up across the Nation. Gangs of youths, whose families could no longer support them, rode the rails in box cars like so many hoboes, hoping to find a job."