How can i stop being broody?

I have a 6 year old son and have been with my partner for 3 years. Im desperate for another child but my partner doesnt want any children until hes at least 30 (we are both 23 now) . i dont want to wait until my son is all grown up and start over again. Also i struggled a lot to cope with my first son and im worried about that again as my partner is ill and there is only so much he could do to help. I just really want more children. How can i stop these feelings? I feel like my heart is aching to have another child. Will it ever go away? Ive felt like this for about 6 months now.