Sam Asghari has reacted to Britney Spears' memoir
Spears called Asghari a 'gift from God' in her book
Asghari said he was 'honored' to be mentioned in the memoir
He also said he was 'proud' of Spears for sharing her story
Asghari and Spears have been dating since 2016
Asghari has been a source of support for Spears during her conservatorship battle
Spears' memoir, 'The Meaning of Mariah Carey,' was released on September 29