How can I wake up early in winter? I don't have a fixed routine, and now im always late in winter! : (

Go to bed early. If you are not getting enough sleep, the best thing to do would be to go to sleep early. You can make your bedroom just for sleeping, keep it quite, cool and dark. Also we also tend to not get enough vit d during winter months and that could be an issue. Set an appointment with your pcp to see if there is any underlying cause for you not waking up.
Go to bed early. Have a good sleep hygiene and same eating and sleeping time daily routine. If needed use alarm daily to wake yourself including days off and have same sleep time so biological clock gets adjusted. It may take few months to work so don't get disappointed if you don't see major change right away.