Almost daily for the last 18 months. Secondary doesn't mean less love, on the contrary, however it does mean alot of anxiety and tiptoeing. Sometimes I am not so graceful on the tiptoeing part. I haven't had any experience with lessening degrees of anxiety in this as of yet. I feel guilt for pain that KT and my husband have felt; but not guilt in the development of my relationship with 2Rings.
For the anxiety I have been really lucky in the friends I have made on here- both sides of the fence so to speak. I have gotten really sound advice and thunks to the head- I have not always taken it at first offer, often to my detriment but always eventually concede the point. You know when everyone you trust says "hey, that wasn't the best way to deal with ____________," then you kind of need to take heed(spelling?). I can be brash and quick to temper but usually that is because I am hurt or worried, and need some kind of outlet or action to take away the nervousness/pain. Believe me it is not ever the best way to handle a situation.
I would think that the best way to deal with all of the negative emotions of being a secondary is to be patient, wait it out, don't act before the dust has settled, be as supportive to your lover as you can be and try to understand the fear and insecurity from which your lover's primary is working. It really isn't ABOUT you, it is about them and where they need to find security in eachother. Unless you are overtly or even covertly trying to put distance or distrust between them, you aren't to blame for discomfort between them. Someone on here (LR maybe) has said you can only control your behaviors. You can only be responsible for your own happiness, or journey to happiness. You cannot let the fear of what may happen to them dictate what your relationship is. In short, be true to you (Mono said that I think). And relish in the fact that you can take a break from the drama by it being an LDR.
I am no expert but I know how you feel. Chin up!