It seems like you are going through a lot of personal change at at time when the world around us is also in flux. Thus, it is not that easy to hold on to things that feel familiar and retain your balance.
I am going to first give you some practical things that you can do to improve your situation.
The first thing is to get into a routine of going to bed at the same time every night, and getting up at the same time every morning. Your body needs at least 7 hours of sleep every night, and your sleep patterns will stabilize when you have a routine that your body is used to.
In terms of your eating habits (which will also improve your sleep patterns and make you feel energetic) there are a few basic rules that you can follow:
* Drink 8 glasses or water every day. This will improve your mood - because the water removes toxins from your body.
* Eat at least 2 meals a day. Those two meals should not be the same. Each meal should consist of at lease a portion of protein (e.g. fish, meat, chicken, avocado, seafood), a portion of green vegetables (e.g. salad, cucumber, broccoli, celery, fennel, onion) and a fruit. You would be surprised at how much better you feel when you eat a green vegetable with each meal. Try to stay away from bread, pasta and potatoes.
* Don't eat anything within 3 hours of going to bed.
* You can prepare two similar meals each evening, then eat one and take one to work for lunch.
These eating habits deal with cravings and give you energy.
For a cold sore, the best advice ever (and I speak from experience) is to press a slice of fresh lemon against the spot from the moment you become aware of it, regularly throughout the day until it goes away.
As for your relationship - yes, it is not easy to get over a relationship and it does take time. Here is what I want you to do: Firstly, write a letter to your ex. Put in the letter everything you ever wanted to say to him and everything you liked and disliked about your relationship. Be totally honest, and write until you have nothing more to write. You may want to do this over a period. When you feel you are truly finished with the letter, destroy it. Burn it, shred it, do with it whatever you want - but do not mail it. The letter is for your benefit, not for his. And give yourself time to find the positive outcome of the relationship. How did you gain or grow or benefit from the relationship? If you feel you are still too close to the relationship, ask your family of friends for their views. When you understand how you gained from the relationship, you will feel better and look better - your natural radiance will shine through.
Then you will attract someone who deserves you and you will have the happiness that is yours.
At work, when you feel stressed, find a quiet place (the bathroom is good enough) where you can hide away for about 5 minutes. Then do some breathing like this: four quick breaths in and out, followed by a deep in-breath for 5 counts, and then a long out-breath for 7 counts. Repeat that 5 times. You will feel the difference immediately. I would say do this initially every hour (set an alarm on your phone) and once you feel you can cope better, do it every two hours.
If you do all of this and still wake up at night, get yourself a book and read until you fall asleep again. Don't stress about being awake, and don't get out of bed or do things like drinking coffee, which will wake you up.
Your body will get used to the rhythm of sleep and you will feel better despite the seasons.
Whenever there is a nice sunny day, take a 30-minute lunch break and go outside where you can close your eyes and feel the heat of the sun on your face. This is also where it is important to eat oranges and other tropical fruit which will give you the vitamins your body needs in winter.
Once you have done all these things and developed a new routine, you will feel much stronger and then you can find an affordable and creative hobby that will also help you meet new people.
Many people are going through these changes at the moment. You are one of the few that are aware of it and you asked for help, and I salute you for that.