Was I wrong to open with a singleton lead in this situation?

At matchpoint duplicate bridge, not vulnerable vrrsus vulnerable, and sitting West, I held

♠ AK32♡ J643♢ 6♣ JT82

Partner (East) opened one heart, South overcalled one spade, I raised to two hearts, North bid two spades, and there were three passes, giving me the opening lead.

I led my diamond singleton, and (FWIW) dummy came down:

♠ JT95♡ A♢ JT92♣ KQ64

Partner asked me why i didn't lead her heart suit. I pointed out, with the benefit of hindsight, that dummy had a singleton ace, meaning that we would not take tricks in that suit. Even without the "look," I feared that given my partner's and my heart length, one of the opponents would have a singleton (or void).

Given my singleton, I wanted to be able to ruff diamonds with my little spades. I had two trump "stoppers" and I wanted to save partner's (presumed) heart entry so she could lead diamonds.

I might not have done this with the spade KQxx or QJxx because I would need the "little" cards to protect my honors. But here, I thought best use of the 3 and 2 would be as ruffers.

Was I right to lead my singleton? Or was partner right to insist on a heart lead? Or perhaps the mistake was that neither of us bid three hearts earlier?