Danica Patrick Sends Mushy Birthday Message to Aaron Rodgers, 'I Love You!'

Aaron Rodgers is turning 36 Monday -- and his girlfriend, Danica Patrick, just hit him with a super lovey-dovey note, thanking the universe for making him.

"Happy birthday to my best friend and favorite person in the world," Danica posted on IG ... "You are the one I want to tell my best and worst days to first."

Here's where things get spiritual ... followed by an L-bomb.

"I am so grateful the universe made you!!! The star dust started it all, but you have done nothing but make it better every year of your life."

"Thank you for being the loving, generous, thoughtful, patient, fun, funny, spontaneous, talented, smart, and uber attractive man, that I get to walk through life with."

"This journey we are on.... it’s a really really good one. I love you. Happiest of birthdays yet!!!!!!"

Danica and Aaron have been dating for around 2 years and things got serious quickly -- Aaron first publicly said he loved her in an Oct. 2018 interview.

The question everybody is asking ... when are they getting married?

That's the question Jenny McCarthy asked Danica on her SiriusXM show back in November -- and while DP admitted she WANTS to get engaged, she's not trying to rush it.