Montana Brown says Mike Thalassitis was "misunderstood" and would have "exhausted every avenue to avoid" taking his own life.
The 23-year-old reality star has shared part of the emotional eulogy she read at the funeral of her late pal, which took place at Christ Church in Southgate, north London, last week after he was found dead in woodland last month, and says he must have been "in such a dark place which we will never really understand".
She wrote on Instagram: "Taking my hat off to big M in the sky for those of you who are asking to see my Eulogy... here's just a bit of it. (sic)"
Montana - who met Mike when they were both on "Love Island" 2017 - then posted: "The last surprise was 2 weeks ago and I can tell you now Mike you surprised us all. I never knew that you were in so much pain, and I'm sorry that you felt like you couldn't share your demons with me or your family as Ive spent some time with them over the past two weeks and they're the most down to earth, lovely people and I'm so happy you had such a strong support network.
"So the human body strives to survive, cells regenerate, they reboot, they mutate all to keep the body alive. For Mikes mental illness to push him to the point where he wanted to self destruct and press that final game over button means that he must've been in such a dark place which we will never really understand.
"Mike, i truly believe you exhausted every avenue to avoid this outcome, as I know you knew you were loved, by so many people. You're kind, you're generous and sometimes very lairy.. but that's the Mike that we all cherish and love.
"I know there's a lot of people in the room that would give absolutely anything to have you back. You were so misunderstood, and i feel privileged to have been your friend, and I have to thank you for always being there for me, always sticking up for me and always telling me to stop being such a drama queen.
"You really were the best kind of person and I will always always remember you and learn from this awful situation. (sic)"
Montana also called for Mike's friends, family and fans to "learn" from his tragic passing by changing how they "live [their] lives" and "treat strangers".
She added: "I keep thinking how we move through things so quickly these days, I mean life is so fast paced and people's capacities to absorb something new often becomes maxed out.
"But the whole nation was shocked by this, and this isn't something you should forget. So I'm looking at everyone here right and asking you to change yourself, change how you live your life, change how you love your loved ones and also change how you treat strangers.
"I can see a lot of reality faces in the room, please do not let this pass you by. It's so hard, the rejection, the competitiveness, the need to constantly look like you're ok, on social media. So let's learn from this, we're all in the same boat, we all have the same stresses... (sic)"