Should I tell him...

Me and my partner has been together now for nearly 3 years I got with him pritty much after my ex he just felt like the one and I split up with him when  I went away to work for a month but when I broke up with him I felt like it just wasn't working we only broke up for a week and I slept with two people then I had to come home because my mum had died and he was the biggest support I fell for him again and we've been together ever since I know I was confused and still getting over my ex before wrapped up in my new job working in another country very selfish AND LONG DISTANCE DOESNT HELP. Now I can't help feeling guilty that we are so happy and trying for a baby but I slept with those two guys🙈 I know technically I didn't do anything wrong but morally it's so wrong because we don't do secrets he is my best friend but now if I tell him I know he will leave me as its been too long 😢 and I really couldn't bare losing him it's been over 2 years now and he is my best friend soul mate my world I was still confused about my previous relationship at the time as it had only been a month I couldn't even look at another man now and living life without him oh it's unbarible please help 😭🙈