car accident and settlement

I have an car accident one year ago. It's the other party's fault and he got a ticket.
My new camery was totaled. The total medical cost is around $2000. Currently, the
insurance of the other party offer $3500 for settlement. They said I got to settle it in
two years. After settlement, they will not be responsible for anything relate to the
accident.

Should I accept this offer? Do I need an attorney? What amount is reasonable?
Thanks.