Hi Friend
first you need to understand the nature of depression. it makes you tired and lethargic. people mistake lethargy to laziness but its totally different. ok so remember you are not lazy

. now you are on medication and it feels great but remember anti-depressants can wear-off so that means its dosage might need to be increased or a different medicine needs to be prescribed. call your therapist immediately about this so you don't have to wait until next week. next you feel confused and have lost interest in your studies. this is a very natural symptom of depression, i.e. lose interest in what used to be a pleasurable activity. so don't blame yourself if you can't study and enjoy your classes. you have mentioned your father is very understanding and loves you. that itself is a privilege as you can see many peoples don't get that from their parents. so count it as a blessing. explain to him and ask him to do a little research on his own about depression so that he can understand it better and assist you.
i know you want to get out of this feeling, but everytime you'll get more aggravated because you can't make it go away and it worsens the situation. you will condition the mind, you are failing at every attempt to make it go away. so i want you to accept that you are sick and that you require healing. denial makes things worse. when you accept you are sick you can blame all things like lethargy, losing interest in studies, feeling confused on depression. this quiets the inner turmoil as you don't blame yourself. this enables your healing process to go unhindered. everytime you blame and worry yourself, you flood yourself with toxins which will hinder your healing process.
okay now i want you to distract yourself. watch more comedy and laugh( i make it a point to watch " Just for Laugh gags" daily). if you have a pet spend time with it, they can shower you with unconditional love. try deep breathing for 3 minutes. start slow but make it regular.