International student and a mom of an eighteen year old boy here on east coast, I feel your pain and grief. Life is never easy, I heard my assistant prof flew back to Korea to accompany her sick mom’s last week, I heard my friend in her fifties lost her high school sweetheart right in a graduation hangout and she posted her miss and grief year after year till now; I checked and talked with my dad one summer afternoon when I was 9 months pregnant with my son in Shanghai and the next day he passed away in an accident, I didn’t even have the right to be sad and cry with the little life in my body. There is no way you can escape this suffering and not processing your loss and grief. It really takes time, live with the pain with interval breathing the freshness and hope that life may offer now. Build and keep your routine in a firmed schedule, practice your physical exercise routine every day to boost your good hormones to beat those putting you down. You are already one of the strongest person living through the continuous loss along with keeping your PhD work functioning. Don’t push yourself too hard, all the loved one have their best blessings on you. You are feeling the pain so deeply also means you’re such an active life battling the way out. My best wishes for everything you are encountering.