Barcelona does not need at all to be that careful as not that many games remain and 8 points for Real Madrid to over come they need to win 3 consecutive games and Barcelona to lose 3 consecutive ones.This is highly unlikely as I was searching for the last time they had lost in La Liga and it was against Real Madrid in the distant date of 16 October,from there on Barcelona has 0 lost games in the La Liga and that time is over 4 months now which is impressive to say the least.Based on that I think that Barcelona whatever does in Europa League,in La Liga they most likely will be the winners without problems.
I also have almost the same thoughts as you. because the difference of 8 points is actually quite difficult for Real Madrid to catch up with. But I also think that Real Madrid will at least have more wins in the next matches and continue to add points. but so does Barcelona who will continue to add more points. so the difference in points may be difficult for Real Madrid to follow. But the rest of the game this season is still a lot. so the opportunity for Real Madrid is still wide open to catch up with Barcelona.
I agree with Ahli38 that Real Madrid has chances to catch up with Barça, and disagree with swogerino because there is no need of 3
consecutive loses at all (which is highly unlikely): every draw for Barcelona, if Madrid wins, cuts the difference in 2 points. In 16 matchdays (the ones remaining) chances are that they manage to do it. In fact, a few months ago the situation was the opposite, and look how easily Barcelona has managed to overtake Madrid.