Help me improve my game please!

Hi everyone! I had a match on Voobly (a 4v4 BF on 1.4RC) that our team ended up losing, on BF I am always at a loss on what to do when enemy enters my base (esp. on 1v1s) I would love if you guys could take a look at the match recording and tell me on what areas should I improve and what I should have done once the enemy entered the flank player's base? P.S. Don't miss my Seige Onager shooting Cyan's vills after entering his base after cutting through forest, I wish I had a vill with him xD

Recording: http://ift.tt/2xxNYUl

EDIT: I had a similar 1v1 BF match on AoE2HD on steam (Jap[me] vs Persians) I didn't know what to do after he used Paladins+Seige onager to tear down my walls, I tried putting out halbs but it was too late :/