Don't feel bad, only on a few occations have I felt bad about leaving and they have been the best employers and I wasn't leaving through choice, Dh job has dragged me away, they replaced me, and the missingmum shape in the sand was washed away
I had an amazing job and it just became horrible, the last few months, missing my children because of travel, previously this had been fine a trade off for me being happy working and keeping a roof over our head, but the atmosphere changed, what I was expected to do changed, redundancies happening all over the organisation which increased my work load, I spent most of one morning crying in my office trying to think of ways to brooch the subject with my boss about flexable working at our monthly 1 to 1 in the afternoon and that if this was not possible I would really have to tell my boss how unhappy I was which I didn't want to do as she is really nice (and start job hunting)
walked into being made redundant.
I could kick myself as I am a hard worker but always tell people interviews and working are a 2 way process as is loyality and employers will drop you like a snake if they need to, no matter how loyal you are and if you don't like your job do them a favour if you can't resolve it and start looking to move on, you will not be a good employee if you don't enjoy a job, but actually it was only that morning it came crashing in.
looking back it was the best thing that happened to me, I no longer fitted and it wasn't going to change, I had known the flexible working thing was a no hoper but I was going to ask just in case.
Basically don't feel bad, about leaving, you don't owe them anything but work and the training was to make you better worker, they owe you pay for your work, I bet they gave you time off for training but I you are like me you will have done work in your own time to make up for some work missed as well as on the training.
leave and be happy, they will struggle to remember your name in 6 months.