Why would you do in my position when offered a 10k raise new position mid year?

I’ve been with the same school four five years as a contracted employee meaning I receive no benefits. I am an ancillary teacher who travels room to room with a cart ( they have planned to give me a room but it hasn’t happened yet). I also have an afterschool club, mentor students and generally help out wherever I can.

I absolutely love my job but making 27k before taxes has become very difficult since I lost Medicaid. Today I was offered a full time real teaching position at another school in the same district. The main issue for me is they want me to start ASAP. I feel awful knowing I would leave my students, colleagues, and projects mid year but also this is a huge opportunity with an at least 10k pay increase.

I currently do not receive bonuses or can work summer school. I do not have a teaching certification as this is not required for ancillary in my state. I have a few projects like a grant and school behavior initiative I would like to finish before I leave.

I’m not sure what I’m really looking for here.

There is a lot of nepotism in my school district so the whole hiring process for this new job is very hush hush. Since ancillary is not policed it is very easy for people to get their cousins, spouses, etc. in the position and I came highly requested by several people in my district.

I guess since I can’t really speak to my coworkers about what’s going on I decided to come here. My contract is a one page document that just has my hourly wage ($20/hr) and position. It does not include anything about breaking contract, transfers, etc.

Thank you for taking time to read my post. This is my very first job out of college so it pains me to think of leaving. I knew I would have to leave some day, but mid year is adding a whole new level.