There are "deep concerns" for brain injury survivors after many reported losing rehabilitation services during the Covid-19 lockdown.
A survey by the charity Headway found 57% of people, injured since 2018, had seen face-to-face services stopped.
The first two years of recovery are crucial in regaining skills, such as talking, with fears this could affect future independence.
The government acknowledged it had been "a challenging time".
Headway conducted its survey across all brain injury rehab services, with 1,140 respondents.
It found about 60% of those were frustrated by the situation, their anxiety and depression had increased and they felt more socially isolated.
'Overloaded my brain'
Jane Hallard, 52, from Gloucester, who has used Headway since 2015, said: "Covid-19 has exacerbated my feelings of anxiety and I have struggled to cope with the changes to my routine."
She said "after things came to a head" she started to receive regular phone calls from the charity, and said it was a "relief to have someone to offload to".
While Headway has created virtual support groups, Jean Parker, 68, from the Wirral, said she missed the drop-in centres and found Zoom calls challenging because of her injury.
"I couldn't cope with listening to and seeing so many people at the same time. It just overloaded my brain."
Headway says it is also worried about the future of its services, commissioned by local authorities, after the Association of Directors of Adult Social Services reported just 4% of English councils felt confident their 2020/21 budgets could cover such support.
Headway's chief executive, Peter McCabe, said the survey results were "deeply concerning" and without funding "the impact on society will be catastrophic".
A government spokesman said: "We know this has been a challenging time for disabled people and their families and we have been doing everything we can to support them at every stage of this pandemic."
It said it had provided local authorities with an extra "£3.7bn of un-ringfenced grants" to support them through this time.