One big mess :(, need advice kinda long sorry

AMBERDAISEY

So recently I became a single mom clearly not by choice i was 7 months pregnant when i caught my fiance cheating on me and sleeping with a girl from his work one of which whom knew i was pregnant. so now its just me and the two boys my 21 month old and my 10 week old. Their father is now telling me he wants to try and get back together and that  he misses us. I am afraid that it will just happen again is it wrong to watn to be with their dad? or is it fair for the boys to try to give them a happy home. We do love each other but he spends hours on end hounding me about if i have been with anyone since him.  And i constantly say no because its the truth and any of you single moms wiht two infants knows its so hard to even find time for yourself let alone have time for dating.  So would you try to fix things or just go your seperate ways