Hi Jess :)
It's great that you have been able to identify your anxious feelings, and well done for having the courage to voice your complications!
I have had issues sleeping in the past, similar to how you have described. It sucks! I will speak on this part of your query, as I feel I have a bit of experience here. It's going to be a bit lecture-like- sorry!
The way I was able to overcome patterns of insomnia was through practising deep breathing- if we want to sleep, we should act like we do when we are asleep! Often when we are anxious, we become incredibly worked up, and our breathing cycle becomes very short- in, out, in, out! When I recognise myself 'stress breathing' as I call it, I am often breathing in cycles of 3 seconds in and 3 seconds out- very rapid!
Breathing very rapidly activates our bodies 'fight or flight' response- putting ourselves in a mode of agitation. However, the breath can also be the focal point to reverse this, and place us into the 'rest and digest' mode (if you want to read more about how the breath connects to our body's state, search 'Polyvagal Theory).
When I tuck myself in at night- or whenever I recognise myself 'stress breathing'- I consciously begin the process of lengthening my breath count from 3 seconds in/out, to 4 seconds, then 5, etc.
When we are worried it may be difficult to lengthen the breath- it's because we can't take our mind off whatever is bothering us! A great technique to alleviate this is something I briefly touched on- to count your breathing- count 1...2...3...etc consciously in your head. In this way, you are focussing on something other than anxious thoughts!
One final thing- you are not going to be perfect at this the first time you try it, it takes practice. The idea is that eventually your deep breathing will relax your body and mind and you will drift out of consciousness- however putting it into practice it isn't always this easy! It is important to be able to accept this in yourself (non-resistance if you want to look more into it). For example, you are wanting to change your thoughts from: "I'm not going to be able to get to sleep, oh no!" to "I am not going to be able to get to sleep, and that is okay." Ironically, being able to accept our anxious situation can help reduce this anxious feeling.
Reach out if any of this is confusing! It may seem a bit weird at first- especially the last part about 'non-resistance.'