Hi OP
Gosh I totally get how you are feeling. Single mum too and earlier this year my 19 year embarked off into the big wide world to begin her adventures. I was happy for her to do this as they do need to get out there, so I encouraged her, but kept inside that it was absolutely killing me! I didn't want to show it though as I knew if she knew, she wouldn't go.
My whole life revolved around her. We do everything together, from shopping to walking the dog. So off she went and I have to say, the first two months were probably the most difficult time I've been through. I cried all the time. If anyone asked me how she was, I cried. I couldn't even watch the end of our series as hadn't finished as it was our thing to do.
After sitting around every weekend and not even going out, I knew I was starting to get depressed and made myself get out and do things. I'm just a bit younger than you and realised that I was moping about and it was no good for me.
It's very very hard, people under estimate empty nest syndrome, but it's rough. Our whole world revolves around our DC and then one day they move in and we are kinda just stuck there.
I wish in advance of her going that I had staeted a hobby group or something to make me get up and get out. As I wfh that wasn't great either and I could go days without leaving the house.
It's been 9 months now and things are better. As an aside in the meantime I saw my Dr (for something else) and I just could not told it together, so he gently suggested that the timing was not great a a that I had other signs of peri menopause and the emotional / anxiety side were heightened. So I started hrt and Im less emotional that I was.
I'm in a different routine now, so when dd comes home its great, but I have to change up my new routine a little. Then when she's goes off again, I go back to it.
I started an exercise class too in my mission to get out, which had helped a lot. Maybe you can find some type of group, where other mothers are who k ow what you are going through. I go to a pilates class and although there are a few younger ladies, a lot are my age so they get it and we chat about our DC and update each other on any news.
My dd is thriving btw. I feel in one way I may have stifled her a bit, I see I was depending on her emotionally, more than I should have. But this is fairly normal for a single parent and child as we have all been through some trauma together to be in the position we are.
So my advise, start out slow and try to get your head around the fact that before too long be is going to want to do something else. Find something that you think might interest you to fill your time. I know we feel like we have no time now, but you need to have something there to so your routine isn't totally shot.
And try to think of it from your dc's side. Unfortunately they won't and can't stay with us forever. We just needed to get them to this point, and now they have to go live their lives. And sometimes that does not include us all the time.
Sorry that was long. But I still need to get it off my chest sometimes, even months in. 🤗