Everyone feels this way at some point. Going abroad may sound a good idea, but when you get back it's still the UK weather and airspace you have to contend with, so just get used to it.
If you are looking to go elsewhere for training, I've always found Scotland has the best flying weather in the UK, particularly around Dundee or Inverness, a lot less stratus cloud and drizzle than you get down south, just more windy. All the rain seems to fall on Glasgow.
Alternatively try taking a week off to power through and get it done. How flexible is your work? When I was working full time and doing PPL, my boss was very understanding and I could book a day off, but then if the weather was going to be pants come to work and save the day off for another time.