How do help my plant?

I’ve had this plant for 3 years—it was my mom’s before that. I’ve had it in this corner of my apartment for the past two years, since it’s the one spot that gets natural light. I repotted it last year, and I water it generally every week and a half. But recently it’s been turning yellow and brown, and losing leaves. It reacts poorly every time I water it. How do I save the plant?