Depression and lorry driving

4yorks, speaking from personal experience, go to see your doctor. I had really bad depression a few years back and let it get to the point where it was seriously screwing up my life. The doctor won’t inform dvla/tc unless you’re actually feeling suicidal and he/she thinks you’re a danger to yourself and especially other people. They may prescribe anti-depressants or they may just provide therapy where you talk it out with a counsellor.
You don’t sound like you’re in a full blown meltdown YET, but it’s surprising how quick it can develop into not wanting to get out of bed and thinking you’d be better off dead. You know you’ve got a problem, so please, go see your doc.