Working in an MNC company 'A' for 12yrs 3 months at the Mid-Senior level. The company acquired 'B' and hence both are merging. Been told no positions available at new merged company 'C'. All other employees absorbed and only I have been asked to resign. Have been a solid performer and have a 3 months notice period. Future opportunities limited due to age (45), gender (F), and being in a niche industry and covid period. Bonus is given CY wise and has vested shares (2021,2022, 2023) listed on the London Stock Exchange. How much severance/retrenchment can I negotiate, considering being the sole earner in the family?