Competing at the European Championship for the first time in 25 years, Scotland need to beat World Cup finalists Croatia at Hampden on Tuesday to likely reach the last 16.
After a 2-0 defeat to the Czech Republic on Monday, hopes were not high for the Scots heading south.
But they were inspired by facing their biggest rivals with an outstanding display to keep England’s vaunted attack at bay.
“On another night we could’ve came away with more – but we take a point, it keeps us alive,” Robertson told ITV.
“It’s important to use this feeling and the fans being happy into Tuesday and try and use it to get a positive result.”
Chelsea midfielder Billy Gilmour won man of the match on his first senior start for Scotland.
And Robertson reserved special praise for the 20-year-old.
“I spoke to him in hotel today and just looked at him and nothing fazes him,” added Robertson.
“I believe he can have as many caps as he wants for Scotland, he has a huge future ahead but the here and now is pretty good as well.”
Scotland boss Steve Clarke said his side were unfairly criticised for their performance in the defeat to the Czechs.
Patrik Schick scored one of the great all-time Euro goals from 50 metres in a clinical performance from the visitors.
“I’ve said for a long time we’re a good team,” said Clarke. “I thought the reaction to the game on Monday was over the top.
“We showed the real Scotland on Monday and got harshly criticised for it.”