Steve Cherelle had befriended the girl who was under the age of 16 and cannot be named for legal reasons, Shrewsbury Crown Court heard.
Ms Marion Smullen, prosecuting, said on one occasion while in a parked vehicle in Shrewsbury with her he touched her breast.
She said the 51-year-old also touched her intimately under her clothing at an address later on.
Reading a victim impact statement to the court, Ms Smullen said the girl described being confused and angry.
She said she also became anxious, had flashbacks and suffered breakdowns.
“She describes losing trust with people and that she’s currently on the waiting list to have further cognitive behavioural therapy,” said Ms Smullen.
“She says the whole situation has really messed with her head and has had a knock-on effect with her studies.”
Cherelle, of Cliff Road, Birchington, Kent, pleaded guilty to three charges of sexual activity with a child in 2018, at a previous court hearing.
Mr Kevin Toomey, representing Cherelle, said at the time he was dealing with “significant difficulties” which led him to “behave out of character” and “appallingly”.
Mr Toomey added that Cherelle’s father has dementia and he looks after him.
The court was also told he was grieving for his two brothers who had died, and was involved in an employment tribunal causing him further stress.
Mr Toomey said: “He was under a variety of pressures.
“This is not a man who will be troubling the courts again.”
Judge Peter Barrie said there had been no mistaking the girl’s age and the ordeal had caused her “considerable emotional turmoil”.
He said Cherelle hugged and kissed her, and spoke to her in a sexual way, before he groped her.
He accepted that there had been an element of grooming and the victim made it clear she did not want it to be happening.
Judge Barrie also accepted that Cherelle had stopped and went no further when prompted the last time.
“The effect of this on her has been serious. It’s caused her considerable emotional turmoil,” said Judge Barrie.
He handed Cherelle a two-year prison sentence, suspended for 24 months, during a hearing at Shrewsbury Crown Court on Monday.
Judge Barrie also granted a 10-year sexual harm prevention order and Cherelle will have to follow a sex offender programme.
He will have to complete up to 55 days of rehabilitation work with the probation service and 200 hours of unpaid work.