Should I say goodbye to my girlfriend before leaving?

We have been dating for 8 months, I’m a student in her country but it’s time for me to leave now and she doesn’t know I’m leaving. I love her so much but there’s 90% chance we might not see each other again after I leave. Part of me is telling me to say goodbye before I leave although it will be very difficult saying goodbye, the other part of me is telling me to just leave without saying goodbye which I know is a bad thing to do but might ease the heartache for the both of us. And actually the reason why she doesn’t know I’m leaving was because she’s been ghosting me for 2 weeks now and even blocks in Instagram. I know a lot of people will say just forget her and move on but for it will easier for me to move if say goodbye before leaving and I won’t have any unfinished business with her. But if I don’t say goodbye I know I’ll regret it later and I know she doesn’t deserve goodbye considering what she did to me, but this is about me moving on not her. What do you guys think?