Yellowing cucumber plants

I have grown a cucumber in a pot in a 'shelter' (open fronted small greenhouse). It has grown well and I have fed it with liquid seaweed and tomato feed, alternatively, and had quite a few short cucumbers. However, the whole plant has started to yellow from the bottom up, I have also noticed some sort of leaf miner bugs in the leaves. Some of the upper small fruits have turned brown and/or dropped off. Is the plant going over or could it be diseased?