My husband had a vasectomy last yr, advice pls?

i am a married 23 yr old mum with 3 lovely children aged 4, 3 and 1 but I long to try for another girl to make our family 2 of each so she wont feel left out, but my husband doesn't want anymore children full stop and had a vasectomy last yr. our marriage suffered, but we have somehow got through this and our marriage and life is better now, but i still long for another baby and want some advice or support on my feelings, thanks. you can email me personally on samgibbs2403@yahoo.co.uk