How to bulk remove triple spacing between your italics on websites and stuff

 
(AKA how to remove multiple carriage returns from Wordpad documents and AO3.)
I don't know if I'm the only one who has this problem, but let me describe it, and the solution, and see if it helps anyone else:
I've scoured the internet, and attempted to describe my problem at Reddit, but nobody gets it, it's hard to explain, and I couldn't find examples to show people at the time.
I have several RTF documents made with wordpad.  Document files that go on for 400 pages.  They have italics in them.  If you just copy paste from RTF, websites like Fanfiction or Archive of Our Own or Wattpad will ignore the italicized text, meaning that you will have to go into the online document and spend hours monkishly re-inserting the italics...
UNLESS you copy paste it onto an Openoffice or Libreoffice document, THEN copy paste from Openoffice or Libreoffice directly to the website.
That USED to work.
I put spaces between each paragraph by pressing enter twice.  I've also inserted italics.
When I try to paste them on sites like Fanfiction net or Archive of Our Own, at times something goes horribly wrong, and I get three hard carriage returns between an italic.
In other words, I'll have dozens of horrors like the following:
T (that's right, just the letter T in a paragraph all by itself)
he burglar scowled at the woman.  "I don't believe you're trying.
If you don't open the vault in the next ten minutes, I start shooting." (In other words, the non italic text drops down another paragraph, often with huge gaps in the middle)
This goes on for 400 pages like that.
There's hidden formatting that is impossible to remove in Wordpad.  If there's a way to remove it in Libreoffice, nobody has told me.
And so I'd have to spend hours monkishly removing hard carriage returns, re-connecting capitalized letters with words, re-connecting sentences back together.  I don't have that kind of time in my life.
In case you're wondering, at AO3, they automatically reformat your text to a modified type of HTML coding, but the coder keeps all those nice redundant triplicate carriage returns for your endless pain and agony.
I tried saving it as a html, but the code involves SPAN and other html garbage that does not easily find-replace.
It seemed the only option was to remove all formatting and just not use italics.  
However, I came to a better solution, as ass backwards as it may be:
1. Copy-paste the document into Libreoffice.
2.  Save as html
3.  Open with notepad.
4.  CTRL+H for find-replace.
5.  Find-replace all instances of </i>.  You need to replace it with something non-code related, anything non-code related.  I use (/it)
6.  This is important:  You need to do the original <i> second.  I replaced it with (it)
7.  Open the newly edited website in your browser.
8.  Copy paste the text from the website into a plain text document to remove all hidden formatting.
9.  Copy paste the deformatted text into Libreoffice.
10.  Save the document as html
11.  Replace (/it) with </i>
12.  Replace (it) with <i>
13.  Open the site in your browser.
14.  Copy paste the text into Libreoffice.  Do not copy it into Wordpad or the SOB will remove all the new formatting with nothing.
15.  Copy paste the text from Libreoffice into your Wordpad document AND website.
This may seem like a huge hassle, but compared to spending the next ten years of your life making all those minute changes by hand, it's worth it.
At this point, the AO3 code becomes somewhat easier to manage in a plain text document.  You can find-replace the page break code, copy paste the edited code back into the website, find-replace it again until there's only a single carriage return.