I think the reason Angad was happy to see Kripa at that time, was because he thought they could share their loss/pain together, and wanted to console her as well as himself.
As far as drinking is concerned, I think for once Angad thought the right way and did not drink. If he sat there drinking he would basically be drowning himself in anguish, and try to forget everything, but I don't think he can, cuz guilt has resided him, and to think through to know how he can fix the mess.
People drink to forget their problems, this time Angad wants to solve them
(little does he know, it's not gonna be that easy, he's gonna suffer major to keep his beloved happy)
Adios
Soni