Dear Susan

So long without talk to each other.

-->It's been so long since we've talked to each other!

l lose your cellphone's number.

-->I've lost your cellphone number.

I want to visit in your home next month in December for to be exact.

-->I'd like to visit you in your home next month, in December to be exact.

I know that you are so busy with your work and your husband but I want to talk with you like before.

--> ... but I'd like to talk to you the way we used to.

After university we haven't talked like before and we haven't seen.

--> Since college, we haven't talked and we haven't seen each other.

I want to continue be your friend.

Now, I had to move to other city, you know why.

-->I had to move to another city, you know why.

Well I hope can call with you very soon.

-->Well, I hope I talk to you very soon.

Say Sam hello!

-->Say "hello" to Sam for me!   OR

-->Tell Sam "hello!"

Best regards!
Fer