Get stronger on your main work out.
5x5 is an excellent stand alone work out for strength.
5x10 is more hypertrophy (think 5/3/1 with BBB)
Nothing wrong with add ons, I just don't think you are getting the jist of them. Wendler once said that he regrets talking about Jokers. Not for the results, but for the way people were adding them to every work outs.
Add ons are just that, something you MIGHT add after your work out. Most well thought out programs do not leave much in the tank for "added" strength.
My suggestion would be to concentrate more on your main work out then going on "how you feel" to get more strength gains.