You expected this already. So you are getting spew from a different route than expected. Your W has followed her standard operating procedure i.e. Indirect confrontation.
Why are you feeling guilty?
No you have NOT gone too far. You did whatever you could to protect yourself and your marriage. You were expecting a shirtstorm...
W's sister is not your W. She can voice her opinions but she is not the one married to you. You told her to respect your actions. And that is just what she is going to have to do.
Frac, you dropped the bomb. Sit tight in your bunker. Let the sisters be angry with you... at least they are talking about you and not how wonderful the OM is.... What did your W think would happen when she asked for seperation or D? This is exactly what would have happened isn't it? Think of it this way.... you gave your W what she wanted before she asked for it --- and now she doesn't like it. Tough shirt.