You're not in a Catch 22 if you did not make any kind of committment to her and are not planning on marrying her soon, you are still in the dating phase of things so that doesn't make you obligated to her. You need to sit her down and tell her how you are feeling and that you feel as though she is moving too fast and if she gets angry and breaks up with you again then maybe it just wasn't meant to be for the two of you. It seem like she wants to control every aspect of your life including friends and who you talk toand who you socialize with. That is why you have to do something now and not wait for it to get worse, like her making you lose all of your friend to the point where you only have her. If you do not tell her now she will take it as you being okay with the way she is acting and it is clearly not okay.
Although I can understand her being upset that your ex told you she still loved you she has to have trust in you and the relationship or else the relationship won't last very long. It's time for you to be totally honest with her now about how you have been feeling and let things take their course and if she can no handle it then maybe she isn't the right one for you after all.
Talk to your ex also and tell her you don't love her but you care about her as a friend and tell her that her writing that on your facebook caused alot of problems in your relationship and that you care about your current girlfriend and want to make it work with her, tell her you don't want to lose her as friend but that is all it can be right now. This way you are being honest yet hopefully not hurting her feelings. Explain to your girlfriend that you talked to the ex and told her that is wasn't cool that she was trying to cause problems in your relationship but I must say this may not be the last attempt your ex tries to break the two of you up so be very careful.