Post Maternity Leave

I'm supposed to return back to work in July - after 12 months.

Sleep training isn't going as I hoped for and LO is still BF as if she's a newborn again. She hasn't been left with her grandparents more than 2 hours. I'm dreading going back to work only because of this otherwise I like to go back. I can extend it until Sept. My work requires evening shifts as well and baby still depends on BF to go to bed.

Any tips on how to gradually change this?

I don't know where or how to begin.