Good for you for agreeing to try to liven things up, but it might have been a good idea to think about what you both feel comfortable doing before deciding to introduce something as challenging as dirty talk.
In theory it sounds easy, but it requires performative skills that elude the best of us. Your husband has obviously done his best, but when people don’t know what to say they default to describing what they are doing as they are doing it. Unfortunately ‘I’m putting my X in your Y’ sounds more like flatpack furniture assembly instructions than an erotic narrative, and it is, as you say, a massive turn-off.
It can be really disappointing when something that was intended to improve sex ends up doing the opposite, but if it is any consolation, your situation is not uncommon.
It happens a lot with talking dirty and sharing fantasies, and it happens when couples decide to watch porn together or explore BDSM practices. New activities that were meant to be exciting instead reveal different preferences or sensitivities that undermine the sexual connection.
That is why it is such a good idea to make a ‘yes/no/maybe’ list before trying anything new.
Type up a detailed list of new sexual activities that you think may be interesting to try, and next to every item put three boxes with headings: one for ‘yes’, one for ‘no’ and one for ‘maybe’. You may want an additional text box under each item where you can add more specific guidance on techniques that you do or don’t like. Give one copy to your husband to fill in, and you fill in another.
You need to complete your lists independently so that you don’t influence each other’s responses. When you compare your lists, start with the shared yes items, then look at the items that have one yes and one maybe. This process gives you both a clear idea of what you are open to and what your individual boundaries might be.
If you figure this stuff out in advance you reduce the risk of one or both partners causing offence or feeling stupid. Because you went into this exercise together I don’t think that you should give up, but I do think that you could give your husband a bit more guidance on the kind of things you would like him to say.
Obviously don’t do this during sex. Choose a time when you are both relaxed, and resist the temptation to point out that a running commentary does not constitute erotic talk.
Give him practical tips — for example, suggest that he might turn the volume down and whisper into your ear. For him this will feel a lot sexier and less awkward than speaking out loud.
Knowing and saying what you want exponentially increases your likelihood of getting it, so if you want him to focus on how much he desires you or how hot you make him feel, you may need to literally put those words into his mouth.