Buds not really growing

qual és tu light?

Much appreciated, so if I cut out the nitrogen or cut it back how long until I should see some recovery, would it be a good idea to give them a flush?

The stunted growth is going to be due to Nitrogen toxicity (overfeeding), you can tell this is the issue by the dark, shiny fan leaves. The way you fix this is by cutting down the amount of nitrogen the plant is getting and since you're in the flowering/budding stage, make sure you’re using a formula that’s specifically meant for flowering, or else it could have too much nitrogen.