I am so sorry you have had to feel the loss of your boyfriend and the lack of support from your mum. But there is a saying: “Don’t try to buy a loaf of bread at the hardware store.” You mum has little to offer and you need a new support system. The short answer to your question is YES.
Therapy allows for emotional support through a trained person. The find help tab at the top of the page will direct you to someone in your country who can help you. Families are complex, and it sounds like there is pain in your family that does not allow you to get your emotional needs met. This is always a good opportunity for therapy.