A single word for the state of extreme inner melancholy and wistfulness

I am looking for a word that refers to the state of extreme, deep melancholy mixed with pain, anxiety, and wistfulness; the state in which one feels that their hearts are going to burst with sadness.

Anguish is a suitable word to express the type of pain, a mix of anxiety and grief, that arises when a relationship breaks up or a loved one dies.

Alternatively, another expression which often accompanies grief is sorrow, a feeling which is more intense than sadness.

Sorrow
a feeling of deep distress caused by loss, disappointment, or other misfortune suffered by oneself or others. an event or circumstance that causes sorrow

^{source: Oxford Dictionaries}

Your description reminds me of the expression: Mal de vivre. (Ngram)- whose English translation might come close to:

• Depression of spirits from loss of hope, confidence, or courage; dejection.

TFD