Queen side expansion as Black in the French Tarrasch

I have written before about trying to find a strategy for Black in the French Tarrasch, 3. Ne2. White spends time arranging his pieces, and Black should be able to use that time to his or her advantage, most definitely at club level.

In today's rapid game at the excellently organised Golders Green Rapid Chess, a short walk from Finchley Road tube station in London, I spent the time White used in the opening, creating a huge space advantage on the queenside. 

Everything went smoothly up until we exchanged light-squared bishops (LSBs). White did not really have anything. 

I failed to capitalize, though, and the game ended in a draw. I made the rookie mistakes twice of releasing the tension in the wrong way.

After 17. Qc2 Stockfish reckons that Black is clearly better, yet I could not find the right plan. Exchanging on d4 is the right way forward, targeting the horribly weak b pawn afterwards.

Again, the French turns out to be an incredibly fascinating opening. Heartily recommended!