Warwick is an item-reilant champion who scales well into the late-game. Losing a 1v1 to early-game junglers (i.e. Lee Sin, Elise) is pretty much expected.
Quite frankly, you were already behind after the first death and even moreso after the second. At that point, it's not really a surprise that the snowballed Lee Sin could keep killing you.
Also, you built Blade of the Ruined King on Warwick immediately after Sated Devourer even though you were severely behind. Sometimes, you just have to suck it up and build a couple defensive items; you can always buy more damage later in the game after you've caught up and are bulky enough to survive. Sated Devourer and Fervor of Battle should be enough damage to get Warwick through the mid-game at least. Spirit Visage and Warden's Mail or Chain Vest would have helps you significantly.
If you are against champions who are likely to invade you early (i.e. Lee Sin, Evelynn, Elise, Trundle, Shaco), start at your buff camp or start at the opposite side of the map. The bottom buff camp is the first place most invading junglers check, one of the most valuable camps to steal, and one of the furthest camps from any allied champions who could assist you.
You could have easily avoided dying to the first invade at Red Buff if you had warded the bush over the wall (near Dragon/Baron pit) before starting it. I pretty much always ward my buff before doing it on the first clear because I play "weak" early junglers who scale well.
