There are essentially three ways out of this mess.
vaccination
The best guess is a vaccine could still be 12-18 months away if everything goes smoothly. Scientists believe that this can be an extraordinarily ambitious goal.
enough people develop immunity through infection
Immunise about 60% of the population, so the virus cannot cause outbreaks - the concept known as herd immunity. However, building up natural immunity could take over 2 years.
or permanently change our behaviour/society
This could include keeping some of the measures that have been put in place. Or introducing rigorous testing and isolation of patients to try to stay on top of any outbreaks.
References:
1. BBC: Coronavirus: When will the outbreak end and life get back to normal?
2. Bloomberg: When, and How, Does the Coronavirus Pandemic End?
3. Science News: When will the coronavirus pandemic and social distancing end?