Interesting that neither East's, South's nor North's suit were better than J108xx. I would have X rather than 1♠ on the 1st round, which may lead to the same contract, or may lead to 2NT-3 by North for -150. Having pushed opps to 4♥, I would sit the double. On the line given, it should go 4 off for +800, almost double dummy, but should always go 1 off as forcing declarer with ♦ should be obvious. How about suggesting a coaching session in your club?