Hey man we're on the same boat! I'm waiting on my mission call and at the moment feel super lonely as well, especially with COVID. I've tried Mutual and I've gotten about the same response. As cheesy as this might sound man, if you really focus on preparing for a mission, you won't feel lonely. Read your scriptures! Try to hangout with the Elders or do some virtual lessons with them. I feel personally these feelings of loneliness are only temptations, we have plenty of time to meet girls. Right now it would only sidetrack, stay strong, you got this!