I'm sorry to read about your insomnia problems, Juvy.
You're not alone, it's very common. I'm glad you wish to fall asleep better by " non-medicinal ways ". Drugs ( " hypnotics " / sleeping tablets ) should NOT be prescribed ( or bought over the counter in the Philippines ) without looking for cause(s) of insomnia. Above all, you need reassurance that at your age, while not trivialising your problem, it's highly unlikely to be serious or long-lasting .
Some people have unrealistic sleep expectations ( we need less as we get older ), or understate alcohol consumption which may be the cause. Neither of these apply to you .
1.Transient / self-limiting insomnia occurs in people who normally sleep well and is due to stress, jet-lag, or shift work, for example. Some stress is inevitable for everyone however. Regular sleeping habits are the answer - no daytime naps / siestas, don't go to bed until you feel sleepy, try not to eat or work in your bedroom, consume less caffeine, try a hot milky drink . Don't exercise late in the evening ( although sexual activity can result in good sleep afterwards ). Putting the radio on a timer - up to an hour - of quiet music, jazz if you like it, or even a talking programme, can help you to drift off to sleep. If you still can't sleep, get up and do something relaxing, then go to bed when sleepy again. Try to minimise extraneous noise such as sibs sharing the bedroom, or buy earplugs so you don't hear the cock crowing . The steady background noise of a fan / air con may help. Room temperature needs to be comfortable, not too warm ( whether in Philippines or UK ). Try not to worry about lack of sleep, you're probably getting enough !
2. Short-term insomnia may be related to an emotional problem or medical illness - again not likely to apply to you ! It may last for a few weeks, needs investigation and possibly hypnotics.
3. Chronic insomnia - again not applying to you - is commonly caused by anxiety, depression, abuse of drugs ( including hypnotics ), and alcohol. Sleep disturbance is very common in depression, with early awakening, and the underlying psychiatric condition needs diagnosis and treatment.