yes, I relate too! when you're used to bad things happening or storms coming out of a clear blue sky you do tend to wonder what's coming even when the sun is shining. like not being able to feel safe in relaxing to enjoy it.....I do understand. I've been there a lot.
Now, I try to just be mindful, be in the moment .... if this is a good moment, I am going to enjoy it so I can remember when the storm comes again that after the storm the sun will indeed come again too.
Right now, is relatively peaceful for me in my mind ..... but not so long ago, every day was black as he**, so to me, that the sun is shining is a miracle. Yes, there is the dread awareness in the back of my mind that depression, fear, anxiety, is maybe not so far away for me ..... I am afraid, and yet, I choose to not focus on the dark clouds and storms that may, or will, come, and focus on the sunshine that is MINE in this moment! I will not take that enjoyment away from myself.
You have the right to enjoy a good day and take it into your heart and soul - you have had lots of hard, dark days, and deserve to enjoy ones that are happy and peaceable, too!