Yes! this is very very important. Frustration is the number one LD killer! Sometimes it’s really hard not to get frustrated, but it’s completely worth it to put in as much effort as you can to take it easy. Like when people try too hard to get a LD and don’t get one.
I saw someone compare it once to playing a flute (I can’t remember who it was 
), if you blow harder you won’t play better, you’ll just get more tired and frustrated! You have to practice lightly but “firmly”. So it’s like there’s a right way and a wrong way to dedicate yourself to LD’ing 
EDIT: what I used to do is I would write in my DJ every day after my dreams the highlights of that night. I FORCED myself to write at least one thing, even if it was lame. It really helps the motivation. Sometimes I’d write things like “OMG awesome LD!!” and other times just “only one ND, but vivid moment at one point”, etc.
About meditation, I really believe it helps, specially in case of stress. I’ve wondered if it were possible to get to the end of the day and tell yourself to drop any worries and frustrations into an imaginary box and get them back when you wake up. But it’s hard to convince the conscious mind to let it go. Meditation sure helps you get more control over the inner chatter that keeps you up at night 
You might want to take a look at the how do YOU meditate? topic and The BIG meditation as a LD aid topic.
and don’t worry if you can’t clear your mind and enter a state of total bliss. it takes some time for that, but that doesn’t mean it’s useless to start practicing! 