From your question, I cannot tell if you are a male or female, so I will address both sexes in my answer.
If you are a male, it is common
for the flow of urine to become a problem as you age. This is usually caused by an enlarged prostate, or BPH (benign prostatic hypertrophy). This basically means your prostate gland enlarges, obstructing the flow of urine. Medications can greatly reduce symptoms, and they are usually tolerated well by patients. In your case, it sounds as if the urine flow is really impaired, so I do think you should see a urologist. Not being able to empty your bladder can lead to many other problems, so I would scedule this visit soon. If you cannot afford to see a urologist, then speak to your doctor now about how this problem is really uncomfortable and effecting your life. Perhaps she can start the evaluation of this problem for you. I do not think you should ignore it any longer, as this problem could become worse. You absolutely need some testing (a PSA level, post void urine test at least), which are really not expensive and can be ordered by your doctor's office.
If you are a female, this issue becomes a little more complicated. I would recommend a full pelvic exam to see why you cannot empty your bladder. Sometimes, female organs can prolapse out of the vagina, causing the feeling of tremendous urgency, Organ prolapse can also cause the urine to not flow out of the bladder well. Women can also have nerve problems in the bladder that cause the bladder muscle to not be able to squish the urine out adequately. Again, this would best be evaluated by a gynecologist (especially someone with a urology background). I would do this soon, as this is not a typical problem for women.