having a problem- please help!?

so, my friend and I have been planning to hang out all week, but one of us always seems to need to push our date off till 'tomorrow'... so I asked him if he wanted to hang tonight around 8, and he said sure. well weve been texting on and off all day about what to do so he finally comes up with going out for dinner, and I said sure and asked him if he had any places in mind... he asked what I was in the mood for. I haven't gotten back to him yet even though its after 8. the problem is that just about a half hour ago I think I might have had a mild nervous breakdown or something and im kinda going crazy for some reason and I don't think I should go out tonight, but I feel REALLY bad about postponing our date AGAIN since I work till 5 tomorrow and I feel like im blowing him off since I asked HIM this morning. I just don't know how to ask him if tomorrow would work better for him without possibly making him feel like im blowing him off so he might not want to hang out with me.. I just feel pretty sure that tonight would not work out... please help!