The term "self love" does not refer to romantic love, which is the context being discussed here. Romantic self-love is obviously self-destructive.
And for what it's worth: the term "self love" exists primarily as an empty signifier with no specific meaning other than as a positive framing device for whatever behaviours the person using the term wants to promote. That's why advertisers love using the term so much -- they can use it however they want and never be wrong in how they're using it.