All I can say is

1) Drop the comma

2) What is written makes no sense at all as a complete sentence

Can’t help any more than that as I don’t have any idea what context the sentence is to be taken in

It is not a complete sentence. You can say…

I am simply keeping the lines of communication open between us.

The sentence sounds fine and straight forward.

Lose the comma after simply.

Simply keeping the lines of communictaion open.

It’s not a complete sentence with or without the comma

Hmmmm, relatively, you may get rid of the pronoun in that sentence altogether: I on no account believed i might have those emotions returned, yet i could no longer administration them. i’m so happy now. in case you sense you might have something there, i might suggesting being much extra sparkling fairly than consistent with a pronoun: I on no account believed i might have those emotions returned, yet i could no longer administration them. i’m so happy for those emotions now. OR: I on no account believed i might have those emotions returned, yet i could no longer administration them. i’m so happy now that I relinquished administration.

I just want to maintain open communication with you.

Simply is fine and no, you do not need the comma.

The “sentence” is incomplete and grammatically is not a sentence.