Should I stay or should I go

I've been with my current employer for 3 years. I make decent money and for the most part enjoy my job.

A few weeks ago a coworker was made our new manager. Personally, this call upset me greatly. He had only been with the company 9 months vs my 3 years and I felt I was over looked for the position simply because I'm a woman.

I raised my concerns to the company president and was assured he was made manager because he is a very hard worker. Since being manager his job performance and attendance has gone down hill & I have stepped up to fill in some tasks. I was given a small raise but I feel they just threw some money at me to make me feel better.

I had started looking for a new job, and I think I found one I would enjoy. But I'm not sure if leaving is what I should do. I know the grass isnt always greener, but I feel like I was punched in the gut when my coworker was promoted.

Right now I commute an hour and the new position would be a work from home job. They pay would be just a shade more than I am currently making but I will have to pay for healthcare with the new company.

I feel very torn as I love(d) my job and other than a few management issues it's not a bad place to work.

I also feel like leaving would make my coworkers lives very hard.