Advice would be being honest with your partner. This will affect them as much as it does you. They will hate to see you suffer and by talking and sharing they will be able to support you more.
I'm sure it must be very difficult however I personally have been very grateful to have a husband and family who provide endless support and understand me which allows them to provide me encouragement and empathy when necessary
It may not be a partner, even a close family member or friend can provide you with the psychological support that you will need