The left-back saw his "focus and ambition" publicly questioned by the United manager as he struggled to hold down a regular place in the side following his return to action from a double leg fracture.
Shaw, who joined United in a £27million deal from Southampton during the summer of 2014, was handed his first start in five weeks in the 3-0 Premier League victory at Sunderland, although he was then back on the bench for Thursday night's European tie away to Anderlecht.
The 21-year-old believes, having cleared the air with Mourinho, everyone can start to look forwards.
Speaking to Sky Sports, Shaw said: "The criticism was very hard, but I've had it before. This time around I dealt with it better.
"When I first came to United there was a lot of discussion about me and that was hard, it was something that was new to me. I was used to positive feedback and comments in the media, but coming to United everything changed, there was negativity.
"I took that badly and it knocked me down a bit, but this time I've come back wanting to fight and I want to prove everyone wrong.
"At the end of my meeting with the manager I said, 'I'm going to prove you wrong'. I believe and want to do that, not just for myself but for the fans that have been behind me and supported me through this time."
Shaw could well be drafted back into the defence for Sunday's home Premier League match against leaders Chelsea.
"I can see the light at the end of the tunnel and I want to push for the best from me," Shaw continued.
Read the full article on eurosport.co.uk: Mourinho's public criticism has made me work harder, says Luke Shaw