I'm sorry things have only gotten harder since then.
To answer your question: fasting is essential with SN. It's optional I guess, but if you want the method to work reliably and peacefully you need to do it.
SN is harsh on the stomach. Without fasting, there's a much higher risk of vomiting, which is the number one reason people survive SN attempts. Worse, vomiting can be noisy, distressing, and increase the chance of someone noticing before it's done.
The minimum recommended fast is 6 hours—no food, no drink. Some people extend that to 8–12 hours to be safe, especially if they're not using antiemetics. Water is often allowed up to 2 hours before, but nothing after that.
If you live with family, I know it's hard to find that window but skipping the fast dramatically increases your risk of failure and being found. Some people go for a "walk," book a cheap hotel room, or stay somewhere overnight just to get that privacy and control.