I don't know whether everyone will be able to relate to this because I've tried talking to people but they don't really understand, but here goes...
Basically, I go through phases. Not "I liked princesses for a year and now I'm emo", but "I spent a month obsessing over this and now I don't like it and have completely moved on". It means for a specific expanse of time (ranging from a month to a whole year), I can be obsessed with something and edit my life to accommodate for my new interests, often to a drastic extent.
Last year I was utterly enthralled in astronomy. I loved Doctor Who so much, spending hundreds of dollars on merch. I also desperately wanted to be an astronaut, and started studying advanced physics and learning Russian (I wasn't up to learn physics in school). My life completely revolved around this future career, and I signed up for programs, paid for online classes and planned out my future after graduating high school; I would get a maths degree, join the Air Force for a year then travel to USA to train to become an astronaut. Then it all changed. At the start of this year I...just stopped. I stopped trying desperately and moved on to another dream. Problem is I had paid all that money and spent all that time for nothing. I haven't touched a Doctor Who episode since.
I began to become obsessed with something else: Acting. Marvel was my favourite thing in the universe, I watched all the movies religiously and once again, spent hundreds on merch. I had giant goals to become an actor, and it became the one thing I wanted to do, forget about plan B. I followed casting websites, saved up money to pay for acting tuition and basically planned my future out again, never mind the fact that a career in the arts is nearly impossible.
Right now, I have just "exited" that phase. Sure, I still would like to be an actor but not desperately, I have become entangled into kpop and even though I'm the incorrect ethnicity and can't dance or sing, becoming an idol is a dream. I know all these dreams are near impossible and would take so much work, and I pretend to be committed, but I'm not.
So, I've fallen into a depressed state where I know I shouldn't commit to any dreams because I'll move on eventually and wreck my life for the umpteenth time. All my goals are so high and it breaks my heart every time I fall down to reality, realising that I'll never be so successful. I am not trying anymore and this is horrible. I don't know what to do. Please help.