I only see emails marked with a yellow star in my sent items in IOS mail. How can I see all email I sent?

In the iOS Mail app, you have All Inboxes and Inboxes against the individual accounts.

Whichever Mailbox you are in (All Inboxes or Individual ones) the filter applies to it. Please check if you have set a particular Account Under Filters. Please see the pic below.

Are there anything beyond unread: for example, Flagged, To: Me, Cc: Me, Only Mail with Attacgments, Only from VIP, or Only Mail sent Today.

You need to elaborate on what this "General Filtering Option" is.

Every single email in my sent box has a yellow star because *I* sent it and I'm considered a VIP in the iOS email system. I'm sure it's the same for you. I *don't* have myself listed in favorites but evidently I am considered a VIP just by virtue of owning the phone and being logged in under the same email address. This does not happen to my other email addresses that are not being used as my Apple login. I'm not missing any emails I send from my phone, but if I send an email from my Mac or from another application somewhere it doesn't sync with my iPhone. A great many things don't seem to sync between the Mac and the iPhone, both of them logged in under the same ID, for no apparent reason. Multiple calls to Applecare has not resolved that problem for me. You may not have all of your sent items in your sent folder because you may not be syncing with other instances of your email that originate in other devices. In my case I have to log into my personal email provider — Zoho -- or use their app to see all my sent emails. The lack of synchronization may be due to the fact that I am using a private email address and not one of the free ones which automatically sync everything for you.

The yellow star in all sent emails on your iPhone means that you have marked the sender of those emails as a VIP. When you mark someone as a VIP, you see a star next to their name in the message list and the message header.