Low mood

Recently started to feel really low and don’t know why (I have gad) my bf has the same but worse than me (he has ptsd) and bless him he tries his best to cheer me up with chocolates, cuddles and intimacy. But cannot shake this low mood. Got meeting with occ health tues am thru work to help me with anxiety and depression as it’s affecting my job now but I worried of being signed off sick when I’m saving as much money as I can when I go to London in April by doing overtime or failing my apprenticeship and lose out of future job. Don’t know what to do to help me get thru my day not feeling so low and down in dumps anymore as nothing recently is helping.