Confused on how to grieve

My fiance died last month unexpectedly it gos without saying I’m absolutely heartbroken., but to keep this short the following day I found out at the beginning of our relationship he was already seeing someone else for at least 6 months he was seeing both of us! & even as recently as May this year he’d got in touch with another ex they were emailing for a few months although they never met up. I was also told by a neighbour of his he’d quite often have different women round to his (we didn’t live togther) but im trying to ignore these comments as the neighbour has contricted herself to me. We were only togther just under 3 1/2 years but I though he was my future & that we had 30+ years together, because of what I have found out I can’t grieve how I should and want to, I can’t remember happy times as nearly every happy time we had togther I now know there was a lie behind it even the first time we met there was a lie behind it. I still believe he did love me as silly as that sounds I just don’t think he knew how to trust because of his up bringing but I can’t make excuses from him. I love this man to bits but now also hate him for what he done (if he was alive and I found this out I would have walked away) I’m so confused on how to feel and think, I’m so upset that his gone & I’ll never see him again & then I just get angry with him that his done what he done. Any help would be very appreciated to try and make sense of it xx

Hi Kw, what a terrible situation you find yourself in, how you are feeling is totally understandable, there’s no right or wrong way to grieve, you just have to go with how you feel at the time, and it will get better, but there is no time limit, keep busy and accept the support of friends and family, sending love Jude xx