You can't put images into a text box I'm afraid. Just one of those constraints of HTML. Why does it need to be a text box? What about a nice table with a background colour. That way you can put what you like in each table cell, and still make the page look nice.
Have a look at the "diary" on my website (ignore the lunatic ramblings and have a look at the text and images on the coloured cells). Is that what you want to do?