Just remember that halving also means half production of bitcoins every 10 minutes. The market is getting less and less bitcoins as designed. Supply and Demand...
Also remember that we have gone up from $3000 to almost $14k already. Currently we're hovering around the $10k mark, which is still $7000 higher-- it increased enough to compensate for 50% less block rewards.
If the price doesn't go up much more than what it has already given us, the difficulty will either go down a bit or remain stable. The block halving is very important fundamentally, but it's not a one way rocket flight to the moon.
Another thing is that when the sentiment is going backwards where coins are being dumped on the market, the lower block rewards won't have much of an effect at all-- the price will go down regardless of that.