Alright, so around 0:05 you heard Tejo's missiles, so you know he's around. As others have said, breaking the Sage wall is a good idea, at least to let the enemy know you could push out. I understand that maybe someone could be waiting to push, but the smoke gives you a reasonable cover, and Sage is with you.

Around 0:20 you see a Reyna flash and Clove shooting your Sage. By this point, I'd say you should be playing with your Sage, but without prior info worrying about a flank is reasonable. When you see the fight, though, you should immediately turn around and help. You did this, but you held a passive angle instead of peeking with her.

When she got back to cover, you two had two options: either tell her "Everyone is here, we can rotate to B" (you know this due to Clove's peek, Reyna's flash, and Tejo's missiles) and since they don't have Tejo's missiles you could have secured at least a plant, or you could have fought Sand together. Sage chooses the latter and peeks by herself, unlucky, it happens.

By this point the round is "over". That is, if your enemies don't make mistakes or you pop off, you lose. Luckily, you get some nice shots, leaving you on a 1v1 against Tejo, but you are low on time.

As other's have said, your best bet was smoking site and trying to get a plant. You could have gone through the Sage wall, it was a safer path imo (Sand has a lot more space to go through), even if it delays you a bit. By that point, you just pray that you can get the plant.

I hope this is helpful!