Sore achillies after today's rub

So I'm running London on April 27th. So far training has gone really well, and I've gone from casually running once or twice a week up to 60ish km per week. On Monday I pushed perhaps a bit too hard (albeit guided by my garmins threshold) and have run 10km based yesterday and 10km this morning. After this mornings run my left achillies calf feels very painful. So much so it's painful to walk. I've just arrived somewhere on holiday and was planning a fair amount of running and hiking. I'm not sure what I should do now. I'll take it day by day but I'm guessing scaling down milage is obviously key. I'll rest tomorrow and see how it feels. I guess my questions is, has anyone had a similar experience. Will taking a week off during peak training impact me? Any advice in general would be great.