Why can't I do that?

I couldn't send any messages tonight.
Was it my fault?
I am very very tired. I'm going to bed.
Good night.((+_+))

You wrote this very well!

Why can't I do that?

I couldn't send any messages tonight.
Was it my fault?
I am very very tired.I go to bed.
Good night.((+_+))

Some thoughts if you do not mind.

You can also say:

(adding a comma with a time frame. With the comma they become conjoined thoughts)

I will go to bed, good night

I will go to bed, in a hour

I will go to bed, soon

I will go to bed, now

I will go to bed, when I am tired

I will go to bed immediately