- your responsibility for your own body remains yours - don't abdicate it to anyone else. This is a hard lesson, and most of us learn it a little too late!
One thought - the more sensitive you become the more you can look after your own body, but also the better your aikido is likely to become.
That's really it, in a nutshell. By all means, you want to try and isolate the specific problem you're dealing with, or at least figure it out as much as you can. Don't be too surprised, however, if there isn't a singular fix, and if 99% of that fix isn't a pill or a therapy or a treatment, but things that you yourself can do. It's just that these things aren't "smoking guns", with an obvious direct cause-and-effect connection. For example, carrying around extra weight, particularly around the middle, tends to make you adopt bad posture that can make injury more likely when you come under stress. Likewise, poor aerobic conditioning can lead to stumbling around. Lack of flexibility, well, we all know about that one. But none of these is the sort of thing where you'd say, "Hey, lose 20 pounds or you're going to have a back injury." So people don't do what they need to minimize the likelihood of injury, and even after they get injured, they tend not to do these things, because they don't get an immediate and total fix.
I really believe that physical health is best tackled with a shotgun approach: hit it with a lot of different stuff, try to understand what each individual pellet is contributing, don't expect any one pellet to do the job all by itself or right away. Something to think about.