Dear***,
How are you!
I'm ***.Thank you for you letter coming across the great continent and the ocean. I can deeply feel the sincerity of Adelphi University and I'm really moved. However, it's so sorry that I've given up the idea of studing abroad, for we can't afford the large ammount of money, which is a big deal for our family.
I'm really so sorry if there are any troubles for you.

最后一句,根据对语境的理解,稍做添加修改. Dear***,
How are you!
I'm ***.Thank you for you letter coming across the great continent and the ocean. I can deeply feel the sincerity of Adelphi University and I'm really moved. However, it's so sorry that I've given up the idea of studing abroad, for we can't afford the large ammount of money, which is a big deal for our family.
I'm really so sorry if there are any troubles for you.

最后一句,根据对语境的理解,稍做添加修改.