How can I stop myself from feeling overwhelmed from little problems?

See below. Depends what you mean by little problems -- everyday hassles? First, identify things you can/cannot control. Work on things you can control and let go of things you cannot. Make a goal list for everyday --what would you like to get done; practice relaxation, self-care, good sleep hygiene -- all of these things will help you. If still feel overwhelmed, seek counseling. Good luck!