How can a person get choked up n tear up without feeling sad?

Yes it can happen: Sometimes, when we repress our sadness at the time of a loss or a traumatic event, it can suddenly appear even years after the event which was never processed fully. Consider speaking with a therapist to find out where the tears are coming from, it is healthy to process our sorrow and better late than never.

Defense mechanisms: Sometimes we experience everything connected with a feeling, but not the feeling itself. It indicates that a defense mechanism is operating. Psychotherapy can help you gain more access to the full spectrum of your emotional life, which would likely be helpful to you (whether or not you have a specific, diagnosable "disorder").