help! cant sleep/trouble sleeping?

alright, the story is a bit long but please bear with me!

it started since my last year in college. with the extra study load and what not, i tend to sleep at around 2-3 in the morning and sometimes later than that. but at that time, this wasnt a problem since i didnt have morning classes and waking up around lunch time wasnt an issue.

but now, post graduation, i already moved on in life so of course i have to wake up early every morning just like a normal human being. but every night i would have trouble sleeping. at first it was hard to break my bad sleeping habits. i still would go to bed at around 2ish and have shorter sleeping hours. but now, i have no idea how but i just cant get a second of sleep on most nights. i tried not to think about it but it didnt work so i tried doing something else like reading a book, hoping that ill tire myself out. before i knew it morning came. and of course i cant try going back to sleep by then. i drank coffee to keep me up but really coffee just dont work on me. i would feel so fatigued and demotivated throughout the day and keep on wishing the night would come so ill be able to sleep. and yeah that night i hit the sack early like around 9-10ish and slept like a log.

i thought by missing out a night of sleep and tried sleeping during "normal hours" this bad sleeping habit of mine would go away. but i was wrong. the pattern would repeat more or less the next day. and this whole experience just tire me out physically and mentally.

i am considering of visiting the doc if it still persists in the coming weeks. but any suggestions of what i can do for the time being? from my amateur research, it seems that i have transient insomnia? but im not sure. i do have a lot of things in mind but not up to the point of stressing myself out...

any suggestions would be appreciated!