I just had my birthday and having lost a lot of friends i...

Survivor's guilt can rob us of our lives. You may need to remind yourself that you deserve to live even though they didn't deserve to die. Oftentimes, life and death are random, and the roll of the dice is no one's fault. Consider that your friends live on in you. It takes courage and work to reframe the thoughts that are bringing us down. Thought stopping techniques may be useful as well as rewording the guilt related thoughts with a life-affirming mantra.

Honestly there's only so much anyone can say to help, I would say think about what these friends would say to you, whether they would want you to be sad or would they prefer for you to keep going? There's no reason that they can't still be a part of you while you still keep living your life the best you can and with support from those around you right now because I'm sure the last thing the people you've lost would want is for you to not celebrate the life they had the current life you're having right now.