Shaw has endured an injury-hit first season at Old Trafford but the 19-year-old - making his first appearance in six weeks - produced his best performance in a United shirt, despite the club's 1-0 loss against the Premier League leaders over the weekend.
The former Southampton full-back said in the lead up to Saturday's trip to Stamford Bridge that he would grade himself a C- for his debut season in Manchester.
However, Shaw said his problems are behind him as the Englishman looks to live up to his hefty transfer fee.
"I am still young and coming to the biggest club in the world hasn't been easy for me," Shaw said. "I haven't been playing and there have been a lot of negative comments about me.
"It is something that isn't nice and I've tried to ignore it, but hopefully the Chelsea game is the start of me coming back.
"I am positive. It was my first performance for six weeks, so it was great to be back on the pitch."
Shaw's outing in London was his first appearance since March 9, when he was substituted at half-time in United's 2-1 FA Cup quarter-final loss to Arsenal.
"I saw a comment the other day saying I was taken off at half-time against Arsenal because I wasn't fit enough, but that's not true at all," Shaw said.
"I know what the manager pulled me off for and it wasn't for my fitness because I could have carried on in the game.
"I spoke with the manager about it. I felt my back a little bit and he just wanted to be careful because I am young and hopefully have a long future ahead of me.
"Over the last three weeks, I have learned a lot from him [Van Gaal] and credit goes to him for trusting me in a big game like this one. He has two sides to him, but he is genuinely a really nice guy and a great manager."
