If you want complete control like that, then you must be willing to use the text editor and learn a bit about html. The visual editor does not always give you the precise location of your cursor, especially with images involved.
Here are some articles about coding on this blog which might help:
Codes useful for text widgets
• Formatting text pt. 1: blank lines, alignment, wrap-around, two columns
• Formatting text pt. 2: indents and blockquotes
• Formatting text pt. 3: space between lines, characters, and words
• Formatting text pt. 4: transformations
• Formatting text pt. 5: color, size, and font