Yeah I highly recommend you wear one of these for a bit when you start up again until you get it all the way back. It definitely minimized my flare ups. https://www.amazon.com/Mcdavid-Support-Sprains-Volleyball-Basketball/dp/B01ITAPWQO
I have really weak ankles as well. That + being overweight for 18 years and never building up certain muscles means that I am really prone to ankle rolls.
Some things that have helped me:
-I have these ankle braces that I wear when I played rugby, am rock climbing, or doing rocky hikes. I always bring them backpacking with me although I don't usually wear them. Ankle braces are good for stabilization as you build up muscles but I wouldn't wear them all the time - especially for things like walking - because it makes your ankle reliant on the brace and it never builds up the necessary muscles.
-Spend a lot of time on your feet. You don't have to be running but things like walking and challenging your foot to stabilize itself (walking on sand, grass etc) will make your ankle stronger and stronger
-I went to physical therapy but stopped because $30 a session was too much for me. But take those exercises and do them on your own time. Use a bosu ball or couch cushion and just stand on it with one foot. This is an ankle routine specifically for runners that I've been doing
-Go to a running store or podiatrist and tell them about your pain in flat shoes. The podiatrist gave me a pair of inserts that I wore in my running shoes for the first two years or so.
The good news is that your body adapts and will build the necessary muscles the more you use it! My ankle is so much stronger compared to when I first started running. When you almost roll your ankle it's terrifying but those are actually the times your ankle really learns to restabilize itself. You don't have to force it but things like balancing or unstable terrain can be really good to build up those muscles...just be careful!
In regards to running, find a program and do it. Don't push your body too hard. If you haven't been running consistently as your body has been growing then it's new (and stressful) for your body - give it time to catch up!