Why make this in such complicated way?

On some separate sheet, p.e. SetUp, store start balance, and name the cell containing it p.e. as nBalance0

On sheet Transactions, you'll have a transactions table, with headers like
TransactionTime, TransactionComment, TransactionType, TransactionValue. You may have a calculated column CurrBalance (like your column H) there too.

When you have this table for personal finances, then probably you can have transactions for several years in same table, you may consider the table too big when number of rows exceeds 20000. To avoid scrolling down for new entries, use autofilter to hide all entries older than p.e. a month.

Better is to enter TransactionTime always as date and time, with every transaction time unique - this allows to calculate CurrBalance independently from sorting. Otherwise you have to add additional column(s), and this is more work, than adding some time to date.

TransactionType is optional column. You can define different types to make it possible to get different reports.

TransactionValue has positive values for income, and negative for costs.

For CurrBalance you enter the formula (I use Table formula syntax here, on fly)

I advice to leave at top of sheet some empty rows, where you can enter a SUBTOTAL formula to calculate the sum of filtered transaction values. This gives you a fast and flexible reporting tool. And use Freeze Panes feature to keep subtotal(s) and table headers always visible.

And of-course you can design as much of various report sheets as you want, where you can select a date period (year, quarter, month of year, week, day) and/or transaction type, and get data from Transactions table - formatted as you want.

When you feel, that you want to remove some older data from transaction list, you have to replace the value for Balance0 on Setup sheet with latest value for CurrBalance of records you plan to delete, and after that delete all earlier records.