first of all, such a shame this had to happen in your life. i can't even get close to imagining the pain this separation might've brought you.
anyhow, the tips below might be useful for you (as they've been useful for me) :)
1. allow yourself to connect with your body while you're feeling low. the physical sensations that are contiguous to these emotions might help you identify 'em whenever they emerge.
2. allow yourself to live with such feelings/sensations while they last. letting them sit with you is easier said than done, but that's the 1st step to self soothing
3. find ways to soothe yourself while those feelings are sat within you. it's like "ok, i'm feeling (bad feeling), let me concentrate on that, let me breathe, my thoughts are prolly gonna be contaminated by it, hence why i shall not take said thoughts into account" and many other strategies that only you will be able to pull off, as you know yourself better than anyone.
4. always remind yourself that feelings, no matter how intense they might be... how ever engulfing, suffocating, enveloping they might be... are deciduous.
5. the role your friend played in your life might not be occupied as of now, and it might not be ever again... but trust the proccess. you'll grow around that shard of your life just fine.
i'll sincerely wish for your wellbeing.
:)
