My good friend started working from home last year and she also thought she would love it. It turns out she is dealing with the same issues you are - loneliness and isolation. Her house is small. Her "office" is in her bedroom so she spends most of her time in that room. Long story short - she is looking for another job.

As frustrating as colleagues can be, they do add dimension to one's life. For better or worse, the office is a "community" of sorts and with that can come a sense of belonging. Maybe it is time to look for another job.

Best wishes.