Immersed is a possibility; immerse has sense “To involve deeply [eg] The sculptor immersed himself in anatomic studies”. “I want my whole life to be immersed in this moment.”
Also, quintessence (“A thing that is the most perfect example of its type; the most perfect embodiment of something; ... The essence in a thing that is its purest and most concentrated form”) may be relevant, as in
“I want this moment to be the quintessence of my life”. Either of these examples (with immersed or quintessence) sound well enough, but whether they are sensible things to say is another issue. For one thing, it isn't clear what it means for a life to be immersed, or submerged, or quintessentially found, in a moment. For another, the subtext to “I want X to be Y” is “but it isn’t Y”. Perhaps drop the “I want” part.