Urine retention 40 weeks pregnant

This is driving me absolutely nuts to the point I'm crying out of frustration because I am barely getting any sleep over it and its effecting my daily life. For weeks I've had trouble urinating, I really need to concentrate to start the flow and keep it going and am really pushing hard to get my wee out. It feels like my bladder is full but when I go it's usually a small amount that comes out. Mentioned to midwife few weeks ago and no UTI so I do think it's the pressure from baby. But today is especially bad, I'm feeling the need to go every few minutes and when I try to I'm pushing so hard, it either comes out in a tiny trickle and I feel a stabbing pain in my urethra like there's more to come but it's stuck, or the wee will suddenly burst out for a second then stop. When I feel I'm done a few minutes later I feel a desperate need to go again. It's causing me abdominal discomfort and hurts when I'm needing/after. I'm so worried about what it's going to be like during labour and after birth, has anyone experienced this?