Ashley Wainwright, aged 26, who had last been based at RAF Cosford, passed away unexpectedly at Walsall Manor Hospital on October 8 after taking dozens of pills in what his fiancée believed to be a 'cry for help'.
His family have raised concerns about a substance injected into him by nurses to calm him down, shortly before his death, which they were told would stop him breathing if he was given too much.
While they have also claimed he was neglected by mental health services at the Army which would not grant compassionate leave to see his father and then failed to contact him for 14 months when he was registered as AWOL, it has been alleged.
The first day of an emotional inquest into the death of the serviceman from Sutton Coldfield, held at Black Country Coroners Court, ended controversially following an angry exchange between consultant psychiatrist Dr Geoffrey Reid and Ashley's mother Martha Geraghty who claimed he 'laughed in her face' after she called him a liar at the hearing.
Earlier Ms Geraghty had given evidence explaining that Ashley's problems had started in late 2012 after his father Lee was diagnosed with prostate cancer. He asked for leave so he could spend more time with him but the Army refused and in January 2013 he was deployed to Afghanistan against his wishes.
After returning from the tour in June he 'wasn't the same' and suffered from intense paranoia which at one point led him to think two flower pots outside the home were snipers, his mother said.
Then on September 16 that year he was given the devastating news Lee had been taken to hospital in Ireland after suffering a brain haemorrhage and was placed on life support.
But when Ashley called MoD Donnington, where he was based at the time before being later transferred to RAF Cosford, he was denied compassionate leave, according to Ms Geraghty.
She said: "The woman on the phone wasn't interested in the situation. She was just screaming and shouting. I couldn't believe it.
"We had to make a decision what to do and the only option was to go to Ireland anyway."
Following Lee's death Ms Geraghty said her son was 'punished' upon returning to the barracks and made to apologise only for the Army to grant him compassionate leave in retrospect.
She said in the months and years since, Ashley became very resentful towards the Army, meanwhile his mental state deteriorated saying he would become increasingly withdrawn and depressed, whilst his symptoms worsened around the anniversaries of his father's death and birthday.
He had also spoke to GPs about his problems as well as occupational health at the Army but said he was not getting enough appointments, the inquest heard.
Ms Geraghty said: "If the Army had done what they should have done in the first place and looked after Ashley and not sent him to Afghanistan when his dad was ill we would have never have ended up where we are now."
At some point in 2014 the inquest heard Ashley failed to return to the barracks and was registered AWOL. Ms Geraghty said her son constantly feared he would be found, but it was not until mid 2015 when an AWOL officer made contact because a warrant had been issued for his arrest.
Her other major concern is Ashley's treatment at the hospital.
She said: "There just didn't seem to be any panic at how serious it was.
"The nurses said he was fine and what was in his system would wash out."
Concerning a syringe given to Ashley not long before he died she stated: "Why would you give him something which could stop his breathing when it was his breathing he was struggling with?"
In 2016 Dr Reid had diagnosed Ashley with a major depressive illness stating he was prescribed anti-depressants and anti-psychotic drugs (tranquillizers). The consultant told the court Ashley would come off his medication against advice when he felt he was getting better leading to further depressive episodes, whilst stating he missed around dozen appointments during a 10-month period.
But Dr Reid prompted outrage from relatives upon finishing his evidence when he appeared to crouch down and speak to Ms Geraghty.
She told court the expert witness said words to the effect of 'we seem to have a different opinion of events' and then laughed when she replied 'I think you're lying'.
Coroner Zafar Siddique recalled Dr Reid back to the stand to respond to which he said he meant no offence and apologised, prompting another angry outburst from Ashley's relatives.
The inquest continues.