It is attributed to him on various famous quote sites but strikes me as spurious. the only source attribution is to Letters to Milena but I haven't read it in years and don't have a copy.
The earliest version of this quote that I was able to find appeared on Twitter in February 2013.
i don't know if i want to drown myself in love, vodka, or the sea
@ChilllSlut, 2013-02-18 11:15. twitter.com.
The quote became popular on Twitter immediately: if you do your own searches, you'll find many hundreds of instances. The attribution to ChilllSlut was quickly stripped, but it took a while for the attribution to Kafka to be added: the earliest instance of this that I was able to find is from bunsonganak05 on Instagram in 2016. The false attribution was copied to collections of quotations, and from there into print in 2019:
“I no longer know if I wish to drown myself in love, vodka or the sea.” — Franz Kafka
Hugo Chandler, ed. (2019). Franz Kafka… Whispers in Prague, p. 14. novum publishing.