Because of/Due to/ due

Are the sentences below grammatical?

  1. I felt depressed on and off the whole day.

  2. He talked to Ganga via Viber regarding his life. (a) He could not
    express his main points to her because of the line disconnection in
    the middle of their conversation. (b) The line got disconnected due to
    zero balance on his cellphone. The talk did not produce anything
    worth keeping. (Is it possible to make a. and b. as one sentence?)

  3. Her next rent is due on August 1.

Thanks

a) He could not express his main points to her because the line was disconnection in the middle of their conversation.
(b) The line got disconnected because he did not have any credit on his cellphone.
The discussion was unproductive anyway.

He could not finish explaining his main points because they were disconnected as he ran out of credit on his cellphone, so/and/but the discussion proved to be unproductive.

Beeesneees,
Instead of
“He could not express his main points to her because the line was disconnection in the middle of their conversation.”
can I write
“He could not express his main points to her because the line was disconnected in the middle of their conversation.”?

‘Disconnected’ is correct. I accidentally omitted to correct that word in the original.

Thanks for your suggestions but what about the sentences 1. and 3. Are they grammatical?

Is this okay?
The way (the) things are going on in my life at the present time, I deduce that I am sinking further and further into depression.

[How about using the word “infer”?]

Many thanks.

I wouldn’t use either ‘deduce’ or ‘infer’ with that sentence. Sinking into depression is not something which I believe someone would generally give such specific type of consideration to. I would just use ‘feel’.

Things are not going well for me at the present time. I feel that I am sinking into depression.

Now,

Her rent is due on August 1. (Is this one acceptable? )

OK

OK as long as you are clear that the date would not be read/said aloud as ‘August one’, but would be ‘August the first.’

Thanks a lot for the explanation.