Formatting toolbar in Apple Mail disappeared

My problem is twofold. First, I noticed that suddenly, the formatting toolbar in Apple Mail – the one that allows me to just click on a button to italicize something or made it broad or something else – had just disappeared. I Googled a lot but got nowhere with the suggestions: I couldn't even click on the "A" button in the regular toolbar, because there isn't one there.

Then, having updated my OS (System Preferences suggested some), I found that in addition to there being no formatting toolbar, many items in the menus at the top of the Apple Mail screen are now gray. And by the way, according to one item I am able to see, I'm using Rich Text, but in one of the menus, it offers to choose Rich Text (but trying to click on it is useless).

I really have come to the end of what I can do for myself at this point. Can any of you help me? Much appreciated, if you can.

Thanks very much,

jenny