To start with , I want to tell you that you have done a good job by asking your query as it may be the starting point of a serious problem and taking consultation early makes it easier to resolve it.
Now to respond to your query , that you feel low in mood and energy, a generalized lethargy
and not enjoying your surroundings , expericing dizziness
and preference to be alone , I would like to say they are features of depression
Though you have mentioned that you have some personal problems and not able to resolve them and don't have anyone to share them with but still even if your symptoms are secondary to your stressor , I would suggest that you should consult a psychiatrist
.your condition is treatable and you will be able to deal with your situation in a better manner after treatment by psychiatrist.
Psychiatrist after detailed evaluation will be able to tell you that you need some psychotherapy
or medication or both depending upon your preference and requirement.
Hoping for faster recovery