Simple Past tense or Present perfect tense?

[Martina Durisova]

I would like to ask for help with the correction of tenses.
I am writing a letter to my friend and I am writing her:

• I have a great time because I found a great boyfriend. Are the tenses correct?

Shouldn´t I use:
I am having a great time because I have found a great boyfriend.

What tense shoud I use at the beginning:

• In my letter I will write you./ I am going to write you or/ I am writing to you about the life of teenagers in Slovakia

Thank you for the help!
Martina Durisova

[emsr2d2]

I would like to ask for help with the correction of tenses.
I am writing a letter to my friend and I am writing her:

• I have a great time because I found a great boyfriend. Are the tenses correct?

Shouldn´t I use:
I am having a great time because I have found a great boyfriend.

What tense shoud I use at the beginning:

• In my letter I will write you./ I am going to write you or/ I am writing to you about the life of teenagers in Slovakia

Thank you for the help!
Martina Durisova

I'm having a great time because I have found (or I found) a great boyfriend.

In this letter, I'm going to tell you about the life of Slovakian teenagers.