Occupational health should be there to support you in your quest to return to work when the time is right for you. They may want to discuss how your employer can help in making any adjustments to ease your return.
I understand your anxiety when you have been off work for a while but please concentrate on being in the best of health. Ultimately that's good for you and your employer.
My experience of Occupational Health is that they are super-supportive and totally on the side of employees. Hope this is your experience too. They will automatically see anyone who's been off work for a while and it's not anything to fear (but understandable that we should feel apprehensive if we are called in to see them).
As Langdaleman says they are there to help us get back to work, as and when the time is right. In the meantime they will just be checking in with how you are, as employers have a duty of care to staff and must keep in touch when someone is on sick leave.
