How to be less vulnerable to ganks (top)?

People suggested I ask a VOD request about this, so here I am.
When I play pantheon I play too agressive cause I feel like I don't have many other options, and as a result I get spamganked. My last pantheon game (https://www.op.gg/summoners/euw/RavioliMafiosi-EUW) I played against Nunu and he haunted me the whole game, even though I ended up winning through some good ults and picks.

How can I make myself less vulnerable without falling off and ultimately countering myself?
tyvm