OutOfMemoryException

I am using FluentNHibernateStorage and getting OutOfMemoryException after running windows service for 5-6 hours.
Also memory utilization keeps on increasing once I start service.

[(null)] 2018-09-14 07:10:50,279 [Worker #a751cba4] INFO Hangfire.Server.Worker - Error occurred during execution of ‘Worker #a751cba4’ process. Execution will be retried (attempt #2) in 00:00:02 seconds.
System.OutOfMemoryException: Exception of type ‘System.OutOfMemoryException’ was thrown.

Below are options-

var options = new FluentNHibernateStorageOptions
{
TransactionIsolationLevel = IsolationLevel.ReadCommitted,
QueuePollInterval = TimeSpan.FromMinutes(5),
JobExpirationCheckInterval = TimeSpan.FromHours(1),
CountersAggregateInterval = TimeSpan.FromMinutes(5),
PrepareSchemaIfNecessary = true,
DashboardJobListLimit = 50000,
TransactionTimeout = TimeSpan.FromMinutes(2),
DefaultSchema = null // use database provider’s default schema
};

        FluentNHibernateJobStorage fluentNHibernateJobStorage = FluentNHibernateStorageFactory.For(ProviderTypeEnum.OracleClient10Managed,
          Oracle_Connection_String,
           options);

GlobalConfiguration.Configuration.UseLog4NetLogProvider().UseStorage(storage);
Hangfire.GlobalConfiguration.Configuration.UseStorage(storage);
Hangfire.GlobalConfiguration.Configuration.UseActivator(new ContainerJobActivator(_container));
BackgroundJobServerOptions backgroundJobServerOptions = new BackgroundJobServerOptions();
backgroundJobServerOptions.HeartbeatInterval = TimeSpan.FromMinutes(2);
backgroundJobServerOptions.SchedulePollingInterval = TimeSpan.FromMinutes(2);
backgroundJobServerOptions.WorkerCount = Environment.ProcessorCount * 5;
HangfirebackgroundJobServer = new BackgroundJobServer(backgroundJobServerOptions, storage,
storage.GetBackgroundProcesses());