I don't think you can truly deal with an existential crisis, or at least "deal" is not the word I'd use to describe it. You have to face the fact that existence is suffering, and accept that as a reality in your day to day life in order to really get rid of the anguish and anxiety that stems from an existential crisis. Distracting yourself from that reality with mental/physical activities only works in short term to get rid of the feeling of anguish, but they always come back. Anyone's who been through existential crises knows this.
Become comfortable, but don't be complacent. An existential crisis like most other problems, ex. weight loss, addiction, self-esteem issues, etc. in the sense that ignoring the problem is detrimental to getting better. The goal is to solve the issue, and the first step to solving it is acknowledging it. After you acknowledge it, it's really up to you to decide how you solve it.