And why shouldn't I be?

A Good Man Goes to War happens before The Pandorica Opens in River's Timeline. In that episode, she bought a vortex manipulator from Doriam.

But if Doriam lost his head in episode 7, then how could he have given River the vortex manipultor in the first place?

But remember River is a time traveller too. She may have obtained it from him earlier in his time line

Surely she would have needed to travel back in time for that to happen, and before the Vortex manipulator, she apparently had no access to such time travel :/

Exactly. AGMGTW happens after TPO for The Doctor and Dorium. Who knows where it crops up in Rivers timeline, it's complicated by the fact that she's in it twice at different points in her life (In stormcage, fairly late on, on Demon's Run, seemingly early).

Was it confirmed that it took place before PO?

Well what date was that battle supposed to take place? I can't remember, did it say? She got the vortex manipulator from him in Pandorica Opens in 5145 so if Demon's Run is after that then it makes sense

Her parents are the Doctor's companions...I think we'll find she did have access from quite an early age

Dorium got to Demons Run with the Doctor - who travels in a time machine ...

It would be later than TPO in Dorium's personal time line, obviously!

Which also means we can still see Dorium loads more as long as it's earlier in his personal timeline!

and he's blue!

Like all the best duckers & divers, crafty cockneys, wheeler dealers, Delboys and Arfur Daley types - he's on his own side

How old Is River Song ?

It's never been mentioned. The only time we know her exact-ish age is at the end of The Almost People, where she appears to be minus a few minutes old.