"Thank you all for helping me through this time with your enormous love & support. Cory will forever be in my heart," she tweeted on Monday, July 29.
She also posted the picture above of the two in happier times, cuddling on the beach.
Michele, her fellow Glee co-stars and show co-creator Ryan Murphy held a private memorial for Monteith Thursday, "to share memories and music in an emotional celebration" of the late star's life.
Monteith died from a mixed drug toxicity, involving heroin and alcohol, on July 13.
Star Sightings: Celebrity Candids
Are These Celebs Too Tan?! Cast Your Vote!
- Arts & Entertainment
- Cory Monteith
- Lea Michele