Unable to download mail using Outlook client

I had been using Outlook as mail client.  However, I got hacked and lost all my mail on the client.  When I attempted to download mail all over again from the Gmail server, I encountered three difficulties:

1. Sent mail wasn’t downloading.  When I called up Microsoft and asked for help, they first said that Sent Mail is stored in your Sent Mail Folder on your client.  When I said that I am looking to download all Sent Mail of the last two decades, they said, “Google doesn’t allow downloading it”, which I know is not true because other clients are able to download all mail, including Sent Mail.  Is there a way to download all Sent Mail historically into Outlook client or other place and import it into a folder in Outlook?
2. Email I send from my phone/s doesn’t get downloaded as Sent Mail by Outlook.  Is there a way out?  IMAP doesn’t help here, since I want to use my only computer and my two phones.  Also, I find IMAP uncomfortable as a protocol for other reasons.  I have over 150,000 emails on the server.
3. After downloading a little over a decade of email, Outlook stopped/paused the download.  I don’t know how to get it to continue.  Clicking on <Send/Receive all Folders> doesn’t continue the download.  Why is this happening and what is the solution?

I would greatly appreciate a way out of these problems and look forward to replies.

Thanks and Regards,

Conscience