Sounds like you have mounted your lens without locking the camera lens mount to infinity first and without paying attention to keep the lens itself set to infinity as well before engaging the lens into the camera lens mount, and turning the lens mount guard counterclockwise until it locks in position. To get a stuck lens, you may have done both : as xayraa33 wrote, it can happen that you forget to set the lens itself to inf. before mounting it, but this only makes that the lens focusing ring is uncoupled with the camera helical for a while, until you realize your mistake and set the lens to inf. and ear the desired "click".
Does the camera focusing wheel still rotate ? Maybe. If so, gently turn it fully to the left (when looked at from above, camera back towards your chest) and keep it fully pushed that way with one finger, then try to gently rotate the lens focusing ring to infinity as well. It it works, you will ear a "click" and then you'll have resync'ed the camera body helical and the lens helical, and you'll be able to gently take the lens off the camera body, like normal people.
Other idea which may work out : do the same as mentioned above with the camera focusing wheel, firmly keep it fully rotated towards the left (ibid) then try to remove your lens normally by pushing the lens release lever and rotating the lens mount guard clockwise. Actually, both your lens and the built-in camera helical may be in intermediary positions so that you can never reach the bayonet sectors disengaging point, when you try to remove the lens the built-in camera helical sectors follows the lens bayonet sectors and so, they would never disengage from each other.
Worse case, if everything is strongly stuck, camera focusing wheel included, the three male sectors of the lens bayonet are now jammed outside their normal position in the camera helical female matching sectors. Trying the get the lens out of there using force will work but it will for sure damage the lens bayonet male sectors, made of soft metal while the camera helical elements are made of solid brass. The remedy is to remove the lens mounting guard collar, the camera front plate, then to dissassemble the built-in camera helical to have access to things from their backside and typically use tiny bits of penetrating oil to carefully unjam the unfortunate lens. An experienced DIYer's or repairer's task.
