I concur with josh re where the bidding went wrong and how to play the hand.
In answer to the next question, after 2
♠, the first issue is the level to which you have forced the partnership. I expect some controversy here, but my take is that while I play reverses as 'strong'.. that is to say, that I require more than most do before I do reverse, it is not gf.
Therefore, I would allow responder to pass 3
♣ if very weak, and with no preference for diamonds. So we have to ask whether, in the context of the auction so far, opener can risk a non-forcing call.
My view, which won't likely be shared by all, is that he can. Imagine partner with the same spade suit but 6=3=3=1 shape and no side Queen. If that is consistent with your methods (which it won't be if you play weak jump shifts), then obviously 3
♣ is high enough.
The alternative would be 2N, but I can't bring myself to do it with this shape, including the void.
Responder has a clear 3
♦ call, and opener can be sure this is 4 cards.. even with a void in clubs, responder can pass 3
♣ since opener is assuredly at least 6 cards there, and 6 good ones.
Note that this is still an unlimited auction. Responder is unlimited in standard bidding... some people may post that responder had 4th suit available to show a gf, either over 2
♦ or over 3
♣, but I would strongly disagree. Responder had to bid a forcing 2
♠ on all hands with a long suit, else he can never conveniently show the length, so 2
♠ does not deny or show anything about strength, and using 3
♥ over 3
♣ with a good hand and real diamonds makes a mess of later bidding.
So 3
♦ was forcing one round.
Yes, all of this is confusing, but that's often the case in 'natural' bidding.
As opener, I think I bid 3
♥, intending to pass 3N, but expecting to bid 4
♣ over a forward-going 3
♠, and to try 5
♦ over 4
♦.
As I say, I expect that others will have different views on some or all of these points
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari