With all of those issues, I don't know why you aren't talking to your doctor instead of asking for advice on the Internet.
I suppose that really depends on what your definition of "serious" is. Low testosterone isn't something life-threatening, but it does affect quality of life. Some psychologists are now estimating that as much as 30% of cases of depression in men over 30 are related to testosterone levels. The issues that you have mentioned are fairly typical issues tied to low testosterone, along with the Depression that I mentioned, as well as anxiety. Your numbers are pretty much in the neighborhood of where mine are, and I'm 37. I did not have the physical issues that often come with low T, but I didn't realize how bad my anxiety was until I started Testosterone Replacement Therapy, and saw how much my level of general anxiety dropped withing a few days of my first shot.
Your numbers are definitely low, the bottom of the reference range for men my age is 440, and I believe it's higher for men your age, so those levels likely warrant clinical intervention. You will want to follow up with your doctor now that you have your test results. It is likely that he will want to test you again at a later date before starting any TRT, because testosterone levels do fluctuate pretty wildly throughout the day. My doctor offered me TRT the first time that I tested that low, but I wanted to see if I could manage it through lifestyle adjustments, so I took six months to see what I could do, but I was still testing at the same level, so I started with the shots.
Low testosterone effects a number of men from varying ages. I am now 26 and have suffered from low T for the last 4-5 years. I have suffered from the same symptoms as yourself and I would recommend getting a referral to an Endocrinologist who specialises in hormones to determine the route cause of low T.
When considering potential treatment a word of warning from personal experience, when considering going on TRT please be mindful of the potential risks involved for fertility in the future.