From what you have shared it sounds like you got married, had children and your life revolved around that, basically being a caregiver. You are just at a point now where you are recognizing the affects of slipping into that role where you don't have anything for yourself. Caregiver burnout can present as feeling "depressed" and lonely the way you have described. What can help is making time for yourself where you can do something fun and be around others that are doing the same where you can gradually build a social life of your own outside your family and work caregiving roles, yes, work can also be a caregiving role.