To add to what Sicariu has said, make sure that you do have upgrades added each week.
Any resources allocated to your upgrade wont be lost ( unless its the citadel itself and you fail to meet the visitor count). You don't have to collect the full amount of resources to cover the upgrade each week ( at higher tiers its impossible to) - they will carry over and continue your progress until the full amount of required resources are gathered.
If you need any further help, my pm is always on ( im sure Sicarius is too)
Kera
Kera:
Proud leader of Shattered Moon