Hi Tristeve,
it took Martin months to get his energy and stamina back. But what started his recovery was his daily walks up and down the steep High street. He'd drive to the town, then walk all the way down to the bottom (1/2 mile), then back up to the top with a break to chat to his friend the security guard in the Pound Shop, then up to the top where he had a Latte as a reward. The street is a big hill so the return was quite challenging! He could hardly do it at first and was breathless, but after a few days and weeks of this he noticed improvement.
You could borrow a dog if you don't have one and take it for a walk. The consultant told us, walk walk walk and walk and your energy will come back, don't forget your water bottle though. After a couple of months you'll be able to cycle.
Cecilia