GPs are leaving the profession at an increasing rate because they feel "undervalued", fuelling what the British Medical Association (BMA) has described as a "crisis".
Research by the University of Exeter Medical School has found GPs are "fed up" with "unlimited demands" on them.
Doctors spoke of concerns about the risk of litigation and problems with their own health due to work pressures.
The government says it has committed to an extra 5,000 GPs by 2020.
Dr Richard Vautrey, chair of the BMA GPs committee, said: "This is a crisis which we've been pointing out for a number of years."
He said the BMA was regularly contacted by GPs from across the country who are concerned about workload pressures.
"They feel they're not able to provide safe patient care," he added.
The number of full-time equivalent GPs fell by 1,193 in the year up to October 2017, compared to a drop of 97 the year before, according to NHS Digital.
In October 2017, there were 33,302 in England, compared to 34,495 the year before.
Dr Charlotte Ferriday quit her GP partnership in Devon in 2015. She said the job left her burnt out.
"I woke up one Monday morning and I couldn't get out of bed," she said. "For six weeks it was difficult to leave the house and it was catastrophic.
"I found it was increasingly difficult to do the job because I didn't have the resources and services that supported my patients.
"It felt like we were ignored and GPs were not valued by the government."
Researchers in Exeter interviewed doctors and other professionals with direct experience of GP workforce issues in the South West.
They found common themes relating to the perceived value of GP-based care, concerns regarding fear and risk such as medical litigation, and issues around personal, social, financial, domestic and professional considerations.
Prof John Campbell, who led the research and is also a GP, said: "The government has already invested a very substantial amount but the truth is that it's not enough because the needs of the population are accelerating faster than the resourcing of the system."
A recent survey by the same medical school found a third of GPs (37%) in the South West thought it was "highly likely" they would leave the profession within five years
Among the 41 GPs interviewed for this latest study was a locum who said: "GPs tend [to] go down one of two routes.
"They either – to cope with demand – start to cut corners or you overburden yourself and you won't cut corners and that has its consequences at the end of the day."
Another told researchers: "I was just working at such a pace and I knew I was making myself ill."
The Department of Health and Social Care said: "Whilst we recognise that GPs face a great deal of pressure as our population ages, we have the highest numbers of GPs in training ever – more than 3,000 – and have committed to an extra 5,000 doctors in general practice by 2020.
"This is supported by investment of an extra £2.4 billion a year by 2020-21 to improve care and deliver better patient access."
Dr Linda Thomas quit general practice in Bristol to set up an eco-fashion company.
She said: "At the worst stages I would come back from a long surgery and I would be physically shaking because the pressure of trying to meet the needs of all the people, the time pressure, the system pressure, just became so hard just to do what I wanted to do and help people.
"I'm a mum as well, I need to be a whole human being. I can't just be a medic and then nothing."