have name changed for this - dp and I have been living together for 4 years and going out another 18 months before that. Late 40s, all our dcs have left home (we have none together).
I was blissfully happy - everyone delighted, his family, my family, friends of us both, and the relationship I would have said, going extremely well. Dp starting to talk about whether either of us would fancy getting married again (we are both divorced, a long time ago).
then 6 months ago, I received an anonymous letter at work - telling me about dp's past. It contained accusations of him having a drink problem, depression, being a consummate liar, cheating on his exes, not being able to hold down jobs, running up debt etc., the fact that when he met me he was still living with his then girlfriend. I confronted dp, he was so upset that someone had written a letter like this. That some of it was true (like having had depression in his past but he had treatment and recovered, the drinking was linked to this) but some was malicious. I don't recognise the description of him from the letter but it's clear he was economical with the truth with me.
The bit that got me was that he was living with his girlfriend when he met me which he lied about at the time. He told me he was single. I even mentioned how many arseholes go on online dating when they aren't single and he assured me that wasn't him. So essentially he outright lied at the time.
I don't know where to go from here - it's been 6 months and I now find myself still doubting dp. He got a message the other day and he hid his phone - I insisted on seeing it and he said it was a surprise for a party we were having (pre lockdown). We had to cancel the party but I still have no idea what the surprise was and I totally doubt him. When I asked, he said we are rescheduling the party (we are) and I must wait for the surprise till then.
Can this recover? I just don't know whether the trust will grow back or I give up on it now.