Millie Farrow would try to avoid shaking her opponents' hands before games. She was distracted in training by intrusive thoughts. She felt ashamed.
However, she was scared to open up to coaches about her struggles.
The 26-year-old English striker has struggled with obsessive compulsive disorder (OCD) and anxiety throughout her professional football career.
A series of major injuries have only made her professional career more difficult still but following a move to the United States, Farrow is now feeling more positive.
Farrow, now a forward at American club North Carolina Courage, was a talented junior player and represented England's youth teams.
She came through Chelsea's academy and later went on to represent Bristol City, Reading, Leicester City and Crystal Palace.
Her dream to become a professional footballer was on course, but at the age of 14, she started to realise things were not okay.
"I didn't understand it. I spoke to my parents and tried to explain what I was thinking and feeling. It was difficult to do that when I didn't even understand it myself," Farrow tells BBC Sport.
"I discussed it with my GP and was referred to therapy for OCD and anxiety. It really affected me at school. I found myself distracted by intrusive thoughts rather than paying attention to my teachers.
"I tried to hide it because I was so scared to talk about it. As I got older, it continued to affect my life. My therapy was stop-start; I saw four or five different therapists because I moved a lot with football.
"I never spoke to clubs about it. I didn't understand it myself so I thought 'how can I expect others to understand it?' I was so scared I'd be seen as weak and not fit to play."
While hiding her condition from team-mates and coaches, Farrow struggled every day in training.
She worried about cleanliness and wore gloves to shake hands with opponents before matches, running off to the sidelines afterwards to apply hand sanitizer.
"There were so many training sessions that were interrupted by my head," she adds.
"It was constantly affecting me on and off the pitch. I didn't see football as an escape.
"It was sad because I cared so much about my career. I felt I was disappointing people and I was ashamed of myself. It was very difficult."
Millie Farrow suffered an ACL injury while playing in the FA Youth Cup final for Chelsea
As well as dealing with mental health struggles, Farrow's career was interrupted by injuries.
Aged 15 and training with Chelsea's academy, Farrow suffered an anterior cruciate ligament (ACL) injury in the FA Youth Cup final.
"It was pretty traumatic at that age. I was out for about 12 months - football was always a hobby back then so it felt like a really big thing. I was growing and learning and missed out on a lot," says Farrow.
She recovered, signed her first professional contract with the Blues after turning 19 and was loaned to Bristol City.
Still dealing with the daily struggles of OCD, she moved away from home for the first time.
"I made some amazing friends and I enjoyed being around the team and working with the manager," she says.
"I was playing well but then I dislocated my shoulder twice which led to surgery.
"I came back from that injury, returned to Bristol City on loan for the Spring Series but then tore my other ACL before that competition had even started. I felt like my world had come crashing down again.
"I wanted so badly to be able to do well and prove myself. I wanted to make something of my career but [instead] because I was young and going through so many injuries, I lost hope and found it really frustrating."
Farrow recovered from injury and joined Reading on a two-year deal in 2018 only for a stress fracture in her back to derail her progress once more.
Millie Farrow spent the 2021-22 season with Women's Championship club Crystal Palace
Farrow dropped down to the Women's Championship in 2020 and her career turned a corner.
She won the league title with Leicester City and scored five goals in 19 games for Crystal Palace the following season.
A short stint at London City Lionesses followed before she eventually signed for North Carolina Courage.
Now, she has released a book titled "Brave Enough Not To Quit" and is open about her struggles with OCD and anxiety.
"When it comes to mental health, it's down to the individual to take that responsibility and to address it," she says.
"I had convinced myself I could deal with it on my own and it took me years to realise that almost 80% of being a footballer is psychological.
"I always used to do extra things on the pitch or in the gym when I wasn't fully addressing things in my head. I'm less fixated on the anxiety and putting pressure on myself now.
"I've accepted things for what they are and that has helped me get this move to the USA.
"I am able to deal with things better and control my emotions better. I used to let them take over my whole body."