You are not going to find significant financial aid for a second Bachelor’s degree. The second Bachelor’s degree would not help you much towards a US medical degree anyway.
What you really need are the pre-med courses. You can complete these in a year-long post-baccelaureate pre-med program, or at a community college. Whichever way you choose, be prepared to pay for it.
More importantly, you will need to be able to pay for US medical school. There’s no financial aid for international medical students. US medical schools are sticklish when accepting foreign students. For example, they may ask you to pre-pay the full cost of attendance for all 4 years into an escrow account. If you don’t have at least $200,000 available to you, the whole studying-medicine-in-the-US thing is a non-starter for you.