Im so jealous of other people in life and wat i havent got, im jealous of other peoples happiness and wat?

they have, and this enrages me wen i go out, to see smiles, laughter, giggles makes me ANGRY grr, to no i cant have a girlfriend because of my cirstances, i feel ignored excluded from society and life. ive been told to thaat it would be hard for me to even get into employment because ive never worked because of my mental health and that im 29