Speaking as someone who was fired from every job I ever held (self employed now- 14 years), you need to think long term. You have developed relationships with your current employer and the people who work there and you never know where those people will turn up in the future. I have customers that I used to work for that I never thought I would see again in a million years because of how I left. But you do have to put yourself first. Removing 90 minutes of commute time a day and more money is a great step up. Just treat the current employer with respect, maybe really try to help with the transition.