Be open and honest with her make sure she understands you as person

It's not my place to judge your readiness, but as someone who went from a long term relationship immediately into another there's a lot of danger to not having some breathing room in between to work through the grief. Even if that relationship was bad and you're happy to be rid of it there is a lot of your life tied up in it that you need to untangle from your own identity. Slowing down a little bit while explaining to your partner why is a good first step, especially if you are worried about burdening her with your struggles right at the beginning because that puts strain on both of you and affects her ability to learn how to be the kind of support you will need going forward. I know that's a big ask, especially when you've found someone that you want to share all of yourself with, but if she's overwhelmed she can't really understand how to be there for you. Rely on friends and family mostly and use this period to slowly show her the reality of your mental illness in a way that makes her feel empowered to help as she feels able to