Need help & positive encouragement for my husband on limited income.

Been trying to conceive for 2 years but now my husband is saying no to any sexual advances I do plus he can't keep little man up. What should I do since my chances are limited on pregnancy. He teases me extremely hard and doesn't expect me to want him to pleasure me. He has teased me so much that I just want pleasure, then he can't keep little man up to pleasure. We were trying for boys. We have 2 girls under 10 years old; one is 8 years old and mentally challenged. ANY ADVICE & HELP would be appreciated.