That's incredibly impressive that you're only missing these.

(To be perfectly honest, I'm not 100% sure that they are all obtainable, so if you've been trying and failing at some of these, it might be time for me to update the requirements and release a new game build.)

Blank Check - You have to pay for "enough" meals during the game. (You need 9 "points" of payment, which I think can be done by paying Sept 29, paying Sept 30, paying Oct 7, getting money from your parents on Oct 21, and paying Dec 1.  There may be other combinations that work, but it's important to have spend enough that you get a refill from your parents on October 21 to be able to get this collectable.)
Blue Friendship Bracelet - Have enough friendship with Hannah at the end of the game. (You need over 90 points, which now that I look at it, may not actually be possible?)
Blue Towel - Date Carlos and have a threesome with Dan on October 29
Green Friendship Bracelet - Have enough friendship with Jake at the end of the game and not be dating him. (You need over 75 points.)
Orange Friendship Bracelet - Have enough friendship with Nikhil at the end of the game. (You need over 75 points.)
Party Hat Sticker - Date Carlos and have a threesome with Dan on October 29
Voyager Disc 5 - Watch "another episode" with James on December 1

I went ahead and pushed a new game build with lower requirements for the collectables you don't have yet, which hopefully will make them more straightforward for you to obtain. 

Best of luck getting them all!

Hey, thanks for the tips. I replayed the game and now I'm only missing green friendship bracelet and voyager disk 5. I tried many ways to get the green friendship bracelet but still failed haha 😂. I have no idea how to watch Voyager with James on December 1. There's no choice to spend time with him, even the MC is dating him. It's automatically spending time with Adam, Carlos, Dan and Liz having meals @The Yard and watching movie. Afterwards, it's December 2 already