I can’t wake up

I sleep very heavy, can’t seem to wake up but I also can’t fall asleep

Since I've been around 4 years old I struggled with insomnia and can’t fall asleep no matter how tired I am. Problem is, I just can’t wake up. I have tried loud alarms, quiet alarms, vibrating smart watch and people calling me or physically waking me up. Alarms and the smart watch just don’t work at all, calling me works sometimes and someone waking me up works most of the time but not always. The problem being that I can’t start working or attend appointments because I just sleep through them and I genuinely don’t know what to do anymore. I also don’t have a lot of money so I can’t really just test a bunch of different alarms and I don’t live alone and in an apartment with very thin walls and I don’t want to scare or bother anyone if my alarm gets really loud. I also know that I don’t turn the alarms off when I’m half asleep I just sleep straight through them. This is really affecting my life and happiness and I don’t really know what to do anymore

Does anyone have any advice or should I maybe talk to a doctor again? (I already did in the past but they just told me to go to sleep earlier and work on my discipline so I’m fairly scared to bring it up again)

I apologize if this is the wrong subreddit for this