Feeling sad

I have been trying to have a baby for 14yrs now on and off with life's hardship. I am about to turn 40 in few months and feeling very sad, lonely, helpless, depress, old, grey hair, feeling end of life. One thing that has not been answer by God is me becoming mother. God has answered all sorts of my prayers and wanting to be a mother is my most heartfelt and praying. I am asking God to send me my healthy and happy child. I am abou to turn 40 and I never thought I would be an old mom. I have tried IUI, clomaid, birth control, natural home remedies, you name it I tried. After so long I finally found an OBGYN who did all tests from scratch and found out the my tubes are damaged and there is no cure for it. My only solution is IVF since I m 39 and not much time to waste. Next month I m starting my IVF procedure and of pure nervous and scared and top of it money cost is way way too much in USA... WHY????