A legal separation order made by the court would not include a final financial order. So, if you want to resolve finances permanently , you are entitled to apply for divorce on no fault grounds and seek a financial order that divides the parties assets, income and pensions fairly and takes into account the parties needs. The divorce application is straight forward but the financial order and pension splitting is likely to take time and you may need to employ a solicitor to deal with this and the disclosure process. Capital assets and income from all are all taken into account. You have not provided enough details of matrimonial assets and other resources etc but you may not get half you husband's pension if the value of your capital is higher than his and your own pension income will be taken into account as well. You will have to pay for legal assistance upfront, usually monthly, either from savings or borrowing, but if your husband is unreasonable you may get some costs awarded to you.
If you are not divorced and he dies before you, you would be entitled to a widows pension, but you lose this entitlement on divorce.