Low sex drive, ed, but ttc! Help

Hi so my fiancé and I have been together for 2 years (known each other for 8 years) and in the beginning of our relationship we were having sex quite often, like at least 4 times a week. But he's never been able to keep an erection for long and has only ever came during sex twice. He can come during oral or hand.

After a few months he lost his sex drive and it seems to be just getting worse and worse.

He takes antidepressants but these problems started before he took them. He thinks it could possibly be porn induced, as he used to watch a lot of porn a few years ago but hasn't watched any the last few months but nothing has changed so I don't know anymore.

We want to start trying for a baby in the next few months but we obviously need to have sex for that to happen.

It's been over 3 months since the last time we had sex. He has been to the doctor and was given cialis but didn't see much difference. He has another appointment with the doctor in a few weeks but if any of you have some information or advice I'd really appreciate it, thanks!