I cannot use the forward ticket, but I need the return ticket still.
Can you use the return ticket if you cannot use the forward ticket to the destination?
From the airBaltic General Conditions of Carriage:
5.4 SEQUENCE AND USE OF COUPONS CONTAINED IN THE TICKET
5.4.1 The Ticket You have purchased is valid only for the transportation as shown in the Ticket, from the point of departure via any Agreed Stopping Places to the final destination. All of the Ticket’s Coupons must be used in full and in the sequence specified in the Ticket. If the Coupon sequence is not followed as specified in the Ticket, the Ticket can be invalidated.
5.4.2 If the Coupon sequence as specified in the Ticket is not followed, or if other provisions regarding their use are not followed (for example, if You do not show up for one of the flights indicated in the Ticket), We or the Carrier operating the flight is entitled to cancel any or all of the unused flights contained in your Ticket, including Your return flight.
5.4.3 Should You wish to change any aspect of Your flights, and Your Ticket’s Tariff permits it, You must contact Us in advance. We will calculate the charge for Your new flights and You will be given the option of accepting Our offered changes and their conditions, or maintaining the original Carriage as specified in the Ticket.
In other words, no. You must use the tickets in order, and failure to show up for your first flight can result in cancellation of the remaining flights on your itinerary. This is a standard practice of most airlines, though there are some exceptions (e.g. easyJet)
You would need to contact the airline to see what change fees apply to your particular ticket (or whether such changes are even allowed) and whether those fees are cheaper than buying a new one.