I think what your feeling is normal, jealousy is the hardest part to over come when being poly and having a metamour. my big thing with jealous is this, are you actually upset your partner is doing something or is it just that you want to get to do it with them too?
take the secrecy thing, that is something you can discuss with her. My boyfriend and I hold hands and act affectionate in public because we all (we are both married) have agreed that if people find out, they find out. Nudge (BF) and i are already "outted" at work, and some of my family knows. My biggest concern was my spouses family and I asked him if i should not be touching Nudge in public, he agreed that if they saw something its none of their business and they'll deal with it. I couldnt handle complete secrecy either. I have my own family to have holidays with, but would i like to see Nudge at christmas? Of course! so we will probably try to work something out.
I dont think its ever wrong to discuss your feelings/insecurities with your partner, whatever they are. Both nudge and my spouse hear from me whats going on in my head a lot, i think the nature of poly is that you will be discussing relationships quite often.
Also, have you considered dating to take a little focus off this relationship? not to lessen anything, but to give you anotehr focus as well. just a thought.