

Is there any hope for this plant?
Hi, dear plant lovers and knowers!
I got this plant from my moms office after she died, I am pretty sure it is a diffenbachia? When I got it, it had leaves and looked healthy. At one point I repotted the plant with a mixture of houseplant dirt, compost and perlite. Then I had some rough times and I totally neglected the plant, it lost all of its leaves and the tips turned brown and a bit mushy, I have now cut the mushy bits off.
I live in Estonia, the plant sits on a windowsill and receives bright natural light during the spring and summer months. During autumn and winter, daylight hours are much shorter, and light levels are significantly reduced.
The pot has drainage holes and I try to water it when the soil feels dry, but I am afraid I might have overwatered more than once...
Please tell me what can I do to save this plant and bring it to glory or I feel that my biologist mom will turn in her grave and will never forgive me🥲