Hey Willow. I admire you for raising your DD to toddlerhood!
I remember all too well that horrible anxious feeling when you think about being on your own for the first time. I really feel for you.
The best advice I was given was just to take it day by day, hour by hour, moment by moment. Don't put too much pressure on yourself - if a routine makes you feel more comfy, work towards it, but don't freak out if you don't get there. There'll likely be lots of tears - from you and your babies, but you'll get through it! Of course you will, and before you know it you'll be 1 month, 2 months on and feeling more and more confident all the time.
Look after yourself. You are doing brilliantly.