Urgent advice needed

Know this is going to get some slating but really need some advice. I have a little one whos 5 months old. I slept with 2 people quite close together so obviously done a dna test. 1 of the potential fathers took charge of this and gave us the results saying he wasnt the father so the other male stepped up and looked after little one until a few weeks ago when we done another dna as the other male was acting suspicious and wouldnt give us the copy of the DNA and we never seen those and hust went by his word. The newest dna results have come back that the fella looking after little one isnt the father. Little one has his surname etc. Obvioulsy we are all distraught. But now im wondering do i speak to the other fella and tell him he actually is her father, he hasnt made any sort of contact at all from we asked for dna results and he kept fobing us of. It turns out he cheatwd on his girlfriend when i ended uo pregnant but i didnt know he was in a relationship at the time. The fella who isbt the father has decided that he doesnt want to continue being involved with baby which is understandable. Im so heartbroke for my little one. I dont care being a single mum but its just about her actual father im confused as i dobt actually know what those results actually said. Please dont reply with nasty messages i am aware its a messed up situation and i dont need anymore hate. Thanks