Leverkusen just need to play their usual game. As long as they aren't on their unlucky day they should be able to get past Darmstadt obstacle easily. I hope to see as many goals as possible from Leverkusen as well to make up for the last result in the best way possible. 
Besides I don't give it much probability but maybe Bayern Munich might get a surprising result against Gladbach considering their near history. If this happens it would be great for Leverkusen. However it is too optimistic to think about this possibility, right?
It's normal to drop point, and besides that, Gladbach is not a small team to underrate, they are not just in good form this season, therefore. dropping points against them is normal and I am still confident of Leverkusen in this season's Bundesliga title.Besides I don't give it much probability but maybe Bayern Munich might get a surprising result against Gladbach considering their near history. If this happens it would be great for Leverkusen. However it is too optimistic to think about this possibility, right?
Bayern Munich might also drop points against Gladbach because when you go through the statistics of their last five matches, you will see a lot of possibilities for Bayern to drop points because Gladbach is always a strong opponent for Bayern Munich, and now that they are looking a way to accumulate some points in order to move up, I don't think they will take it easy with Munich either.
It will come down to the game Leverkusen - Bayern because this game is going to be one of these pivotal points that are typical either for or against Bayern. If Bayern wins it, things can go its way quickly and Bayern usually capitalizes on those events. This is not to say that it would be over guaranteed if they win that game against Leverkusen, but psychologically it would be tough to cope with it for Leverkusen because then it is not in their own hands anymore.
But I didn't forget about last season when Bayern had it safe already a couple of times, but kept struggling several times and Dortmund was too stupid to not convert that golden opportunity into the Bundesliga title. I hope Leverkusen will be more solid about it.