Help moving from half to full marathon - 5 months to go

Hi,
I did a half marathon on Sunday, my first. I started running in July, so it took me 4 months to get to half marathon. I have been looking and looking at training plans but most seem to go from a standing start and take 16 - 18 weeks. I'd like to (understandably) keep the fitness that I have and build on that to make it (hopefully) a more comfortable transition. I felt absolutely fine the day after the half, ran 6 miles today and legs were very tired first and last mile, though in the middle they felt fine.

Can anyone recommend a training plan/ make some suggestions on how I can best build from where I am to where I need to be? Race is early April. I just want to finish, but as a guide my half time was 2hrs 15.

Thanks :flowerforyou: