What Grog said! It is excellent advice that you go for a professional bike fitting. It's entirely possible that the bike is a frame size too large for you (top tube too long). Or, it may simply be that you need to give yourself time to get used to the different position. As she said, you might require a stem change, though Terrys come with short stems to begin with so if the bike is too long for you, it may be a top tube problem, in which case, you might have to cut your losses and sell the bike.
One thing that is curious to me. If you ride a Terry Classic in a small size such that you have a model with the 24" wheel (the 16", 17.5", and 19" frames are all configured this way, I believe), then I am surprised that your new/old/vintage Terry road bike does not also have a 24" front wheel. It was my understanding that smaller-sized Terry frames have always been made this way. I have a 2001 Terry Isis (17.5" size) with the small front wheel, by the way. I could certainly be wrong, but there's a gal in my bike club with a quite old Terry Symmetry in the 17.5" size, and she has the small front wheel too. So, it's possible you got a larger sized frame. Sometimes buying used, the seller doesn't even know the exact frame size and you aren't buying the size you think. Although....since you mention toe overlap, that would only occur with a short top tube, so it is probably a smaller size....thinking out loud here....
When I went from a hybrid to my Terry, it felt very squirrely and weird at first, but with the short-reach Ultegra brake levers, I was able to ride in the hoods and drops pretty quickly and comfortably. After about a month of cycling regularly, I was quite comfortable on the bike. So, you may just need to give it more time...but a fitting is smart no matter what, especially since you're new to road riding.
Good luck and please keep us posted!
Emily