I am an extrovert too, I do feel lonely when my husband is not around on weekends or holidays or when I fall sick. I constantly have to reprioritize my kid, work, other activities.
If this is his first year, I believe he has at least two more years, possibly as many as four or five. I'm surprised you don't seem to know how long his residency will last.
Of course I feel slighted at times, but I check myself and remember that my SO is doing his best given all his demands.
We are now in Residency, have moved each year and started a new adventure each year since marriage. He is doing 2nd year Residency.