What time of day do you feel sleepy? I often find that there is a specific time of the day when I feel tired and want to sleep, usually around 2pm in the afternoon. If I can overcome this by getting some fresh air and even just a little walk outside I can recover enough to stay awake until bedtime. As for finding it difficult to go to bed if the room is warm I also have difficulty sleeping in a warm room and always need a window open to allow air to circulate, even in Winter otherwise I wake with a headache.
You may also find it useful to read for a while before you sleep to relax yourself.