Maybe I missed this, but I'm curious just how close you stand to the net when your partner is serving? And I am curious if you take a step back or two steps back when your partner is hitting a second serve?
I see so many players standing a foot from the net, which makes them easy targets to either drill or lob. You take chances with this strategy. Chances that you need not take in my opinion.
Drilling someone at the net is part of the game. It happens. It will continue to happen. It's legal, it gets in the head of the head of the person at the net, and more importantly it is a winning strategy if the net opponent is weak on volleys. I'm not condoning it in social play, or mixed doubles, but the fact is it drilling the net player is not going to stop. You have to adjust your game to deal with it.
Venus Williams' doubles partner doesn't have a weak serve, so Venus can stand closer to the net when Serena is serving. Venus is also 6'1". Mike Byran's doubles partner has a pretty good serve as well. Your partner is neither Serena Williams or Bob Bryan, and doesn't have a good serve.
So what can you do?
1) If you play an opponent who does drill you at the net when your partner is serving weakly, don't stand 1,2,3 or 4 feet from the net. Back up!
Move back to a point you are comfortable hitting a hard hit volley, cutting off a volley diagonally, and standing in a position which makes lobbing you more difficult. There is no requirement to stand 3' off the net in doubles. Why not back up 10-12' from the net? The service box is 21' deep. I hit with 4.5 players who volley with great results from 12' feet away from the net weekly. If the return comes at you, you have more time to react or cut it off diagonally.
2) Tell your partner to grab a bucket of balls and practice their second serve 15 minutes per day to improve it. This helps everyone.
Too many players think a volley must be a winner.
This is so far from the truth. Volleys can be winners and often are, but they can also be great set up shots, by placing the ball deep and putting your opponents on the defensive, or hitting a drop volley (again putting your opponent on the defensive) and forcing your opponents to "pop" the ball up. If you can't hit a winner off of a volley, don't worry about it. You can still hit an effective volley and put your opponents on the defensive. But don't "pop up" a volley which gives them the offensive for their winner.