You did at least 3 out of the 6 things needed, hope this helps you get the rest! These are all the things needed to do for the true ending, if there's something you don't understand or if you're romancing a specific character, look at the complete walkthrough in the development log:]
1. Linger at the Graves, leave flowers and get the chain.
2. Hug Toriel.✔️
3. Choose leave Snowdin first, cuddle the dog(you must get him near you first), enter Snowdin, go to the dog trying to catch your attention, you get the stick.✔️
4. Go forward first and sing with Shyren.✔️
5. Help Alphys.
6. While helping Alhpys explore the floor, enter gaping hole in the hallway and choose to keep the paper & save entity every chance you get.