Those tomato leaves could signal a few things, some easy to fix and other much less so. Before proceeding any further one thing I need to know: have you noticed any white round lesion/spot on the tomatos themselves?
As an aside, lack of water does not cause Blossom End Rot (BER). Watering unbalances and lack of calcium in the soil do, and some cultivars (San Marzano and many of its hybrids to say one) are extremely vulnerable to it. BER is cured by a combination of soil amendment (since you grow in containers you can use liquid calcium boosters), regular watering schedules and growing BER-resistant cultivars: no point growing San Marzano in an area prone to almost daily thunderstorms.
Now let's get to that cucumber: it's almost textbook overwatering. The cure is simple: cut the water.
