A depression diagnosis doesn't necessarily mean it will keep coming back. Medication and talking therapies can help and it's advised to stay on the medication for around 6 months after the symptoms stop. The longer it is left untreated, the higher the chance of relapse. The problem we have in this country is mental health services are grossly understaffed and underfunded so we need to keep fighting to get the help we need. There are other resources available though. See if there is a Recovery College in your area, self-refer to counselling to get on the waiting list, contact your local Mind, see what help they can offer.

Stop comparing your life to others. People show the aspects of their life that they want to be seen. It doesn't mean that their life is perfect. Can you contact the careers service at your uni and ask to talk about your options? A lot of universities offer support post-graduation.