I hated my very first job, although my boss was extremely nice. After four months I got another, much better job but was very nervous about telling him, partially because he was such a nice man.
In the end plucked up the courage to tell him I was going the following week (only a week's notice that time) and he said 'Well done, I'm job-hunting too, I can't stand it here much longer, good luck in your new job'.
I was very relieved and hope that he managed to get another job.
Have you been offered another job MissA? If the people you work for now are nice, they will want the best for you even if they're sorry to see you go, if they're not nice then don't worry about upsetting them.
You said you had a long journey to work - is the new job nearer?
Are you going to tell them tomorrow - don't forget we're all behind you! 
I get nervous about booking a holiday online and have to check, double check and triple check to make sure I haven't got dates etc wrong. I also get nervous buying online and envy people who say they buy and sell on Ebay as I just couldn't sell anything.