Speedway bikes have one gear, no brakes, a clutch, a 500cc engines running on methanol fuel and can accelerate up to 60mph, faster than a Formula 1 car.
Heeps said the incident "felt like forever".
"I knew I was going in, it was just [about] when it was going to stop.
"By the time it stopped, I felt I was going very fast and it knocked the wind out of me."
He went to hospital straight after the meeting. His his X-rays had all come back "all clear" but he had been "in quite a bit of discomfort".
"The doctor said I'm going to be very sore and said I have a lot of internal bruising," adding that he was "managing the pain".
"The first two days I didn't really move … it was horrible, I felt useless but I'm staring to get back on my feet."
Heeps said initially his back, ribs and stomach had hurt the most.
"That's all coming down now and it's more my ankle."
Heeps said he hoped to be back "as soon as I can", potentially for the meeting at home to the Edinburgh Monarchs on 18 June.
He said he was "confident" he would get over the issues.
"It might take one or two races to calm down a bit and not be so tense on the bike.
"But if you are riding well previous to your crash, then it will all click back in and you will be straight back into the swing of things."
Oxford Speedway Supporters Club have raised more than £3,000 so far to help replace his equipment.
"I can't say how thankful I am," Heeps said.
The club said it was "relieved" that he had not suffered any breaks even though "Cam says he feels like he's been hit by a train".
"We wish Cam a speedy recovery and look forward to seeing him back on track soon!"
X
