Do daily Luna, give a huge amount of experience

Recovery teas + instances?

go back check if u got any campaign quests left and do all + see if ingssion have any bluequests left u forgot to do.

did u do makarma?

I see what u have done wrong.. i Ingssion u need do all campaigns quests before u hit 56. if u did turn in all instant quests and not have done campaign quests yet u dont gain any xp before all ingssion campaign quests is done. when u go lower udas u should wait for instant quests them before u are 56. if u dont, u turn in like 6-7 quests and dont get any xp.

Im nearly in same position, done all campaign quests before lvl 66 and all blue quests except ''lower udas'' instance.. and im currently lvl 65 (the bar on 90%, which can be easy grinded with mobs).

you have to take all the blue quests u can, complete them, and then do a campaign quest....then more blue quests will unlock...If you do it properly, u should be able to get to lvl 80 with quite a few signia quests left to do.

The trick is not to hand over all the blue quests in inggison as you will get the lvl cap limit and waste exp. Once u finish the campaign quests the you can lvl up and use the blue ones. You'll then not have issues

If you do 100% of all dark Blue quest + compaign + Udas you have no rpoblem with XP normaly.

(All dungeon solo give you auto quest that give u amazing xp)