I suspect this has been discussed before.
If you cannot rebid ♠ (shows 6) then how do you proceed? I don't like 2NT with the weak doubleton, 3♣ seems awkward to say the least, I'm leaning toward 2♥ but with little conviction.
If you rebid 2NT (likely wrong sided), how do you discover if the ♦ are adequately stopped to play 3NT?

Help

With the ops silent you open 1♠ part bids 2♣. What's you call ?