Great answers GG!
I have anxiety issues as well (and severe depression issues).
We encountered a similar issue this winter which damn near resulted in me being put in the hospital for a few weeks.
My first suggestion is to make it clear that your sanity and life depend on your partners being true to the agreed upon boundaries-TO A FAULT.
Second-find another person who can be an ear when you need to vent-but your partner needs a break.
Third-agree on a weekly date time that NO DRAMA is allowed to be discussed-even if there is a crisis on hand-then STICK TO IT together. This was our saving grace.
Fourth-start identifying precisely what it is that sets you off.
(for example, people in my personal space and loss of my date time trigger me, as well as someone being involved with my kids whom I feel threatened by).
Fifth- set up the boundaries around these triggers as a safety net, not limitations-but boundaries.
(example, we have separate bedrooms for other lovers, so the room we share is always "safe" for me to go to anytime-no matter what, and no one else is allowed in that room-ever. Also, we hold our date night sacred. If a new lover is only available that night-we will consider changing which night is our date night, but HAVING it is sacred. And, finally, no one meets the kids now until we're both on board with that person-period.)
I'm sure there are other things that would help, but that's what pops off the top of my head as what helped me the most this winter.
"Love As Thou Wilt"