I think mine in the greenhouse were probably too cold when they first went out, and are too hot now.
I ended up with too many plants too. I planned 12, ended up with 29! I didn't have anyone to pass spare plants on to (one particular friend point-blank refused to even consider tomatoes until she gets a polytunnel, because she was so disappointed in her outdoor toms last year compared to the ones she could grow in London). And I just couldn't bring myself to dispose of healthy little plants, so now I have 12 in the greenhouse, 8 in straw bales, and 9 in buckets on the decking next to the house.
Most of my plants look really healthy and leafy and vigorous and they have loads of flowers, but the fruits are taking aaaaagggggeeeesssss. :(