Withdrawal has many different symptoms.
Withdrawal management is essential to your success and safety. If symptoms become too great or concerning, reach out for assistance to ensure your success but some withdrawal symptoms can be managed with simple tools.
It is not unusual to feel fatigue, depression, anxiety, etc. Do what you can to prepare ahead of time to manage these reactions. Eat well (prepare and freeze healthy meals ahead of quitting), get out into nature when possible, be with friends and people who support you (but not those who share your addictions), sign up for yoga and/or meditation classes (download guided meditations from You Tube or other apps if you are not feeling up to going out in the beginning). Record a reminder to yourself of why you have decided to quit and make sure to include all the benefits you look forward to when you are addiction free in your recording. Play this to yourself as frequently as required.
Ensure that you get lots of rest. Even if you are experiencing insomnia, lying down and resting has its benefits even if you do not sleep. Rest is medicine for your body and mind.
You can do this!