I developed lympodema in my arm, breast and torso. I am not happy about it, but it's manageable. I would rather be alive with it than dead. Not everyone develops it. It's not inevitable. And it's manageable.
I really encourage you not worry too much about it. Worrying won't help and may well be unnecessary.
However, it's a good idea to see a lymphedema physio soon and get measured in your arm so they know your starting point, should it develop later. I wish I had known to do that.
You can also be checked regularly so if some develops, you get on to treating it quickly.
So sorry your chemo didn't work. Best wishes for you next treatment.
karen