I am in a dilemma. Please help!

I have two offers and want to negotiate with the first company now after accepting the offer. The thing is, there was a delay in my DOJ (Initially it was 2 months but now it's delayed by 2 more weeks) and they agreed to it. The first company also scheduled bi-weekly calls with the hiring manager until my DOJ. I don't know how to bring up the negotiation topic now. Also, I feel like I am wasting their time by doing all these, but I have no other choice due to the bad market situation. What do you all think? Negotiate or simply walk away?

Company 1 (Morgan Stanley): 15.01L base + 1L PF + 2.26L variable (1.75L for the first year) + 1L JB Company 2 (Oracle): 18L base + 1L PF + bonus (depends) YOE: 1.6