This is very good news! The drug Prozac, which is an old drug approved for the treatment of depression, OCD, Bulimia and panic disorders, has been shown in mice to help brain tumors! They did a unique type of research to show that it helps patients with glioblastomas: they looked at medical records to see which glioblastoma patients also happened to take Prozac (or it's generic equivalent), and how they did.
There was an increase in median overall survival of glioblastoma patients who also took Prozac of 545 days with Prozac and 318 without Prozac, This is a 71% increase in survival just by adding a repurposed drug, which has the side effect of helping with depression and mood!
The study is too small and not the gold standard randomized phase 3 but the drug is relatively innocuous, cheap, easy to get. Might be worth asking your doctor about it.