plotting – How to properly write multiline text with LaTeX symbol in a frame and with background

I wanted to include a number of text-box with background color white inside a plot. The text inside the box will also have LaTex expressions as well as multiple lines.

Is there any way to include multiline text (including LaTeX symbol) inside a plot?

In addition I want to set frame and background color for the box.
I am currently using Epilog and Prolog to include such text.

  PDF(BinomialDistribution(50, p), k)}, {p, {0.3, 0.5, 0.8}}, {k, 0,50}), 
  Filling -> Axis, 
  FillingStyle -> Automatic,
  Epilog -> Text(Style(ToExpression("\text{E}_{x} \n text2", TeXForm, HoldForm),Bold),{30, 0.13}),
  Prolog -> {Inset(Framed( "E_{x}ntext2" , RoundingRadius -> 5,Background -> White), {45, 0.13})}
(*Prolog -> {Inset(Framed( MaTeX("E_{x}\n text2" ) , RoundingRadius -> 5,Background ->White),{45,0.13})}*)

Option-1 fails writing E_{x} as well as breaking line.
Option-2 fails writing E_{x} but breaks line.
Option-3 is the one I wanted but it fails in breaking line.

Is there any way to achieve this.

Moreover I also wanted to ask, what should one do if one has to include say more that two text boxes?