Delayed ejaculation. Is in trouble.

I think I am facing delayed ejaculation problem. From last 3 months we are trying for second kid, but through natural penetration I am unable to ejaculate. We married 6 years 9 months ago and we had first kid after 2 years with natural ejaculation(unplanned) and that too at first attempt. Due to family issues we never had sex for atleast next 3 years, this is period where i got used to regular mastrubation for self relief. Now as problems solved and even first son age crossed 4 years we thought to have second kid. But during last three months we tried naturally but nothing worked. So I tried approach of masturbation and ejaculate inside vagina. My wife unable to get pregnant with this style and she lost confidence in this approach. During mastrubation, I was able to ejaculate but that same style unable to replicate in natural way. During first two years I used to ejaculate in 5 min or max 15 min. Now due to this continues delayed ejaculation issue , our relation is in trouble.