Your rigging tensions most probably needs to be a adjusted.
Here's the most comprehensive manual available on the internet on how to DIY... look at the section on how to tension WITHOUT a tension gage, just a 'meter-stick': http://www.riggingandsails.com/pdf/selden-tuning.pdf
Simply follow this 'guide' for the 'basic plain-vanilla' tension setting and you'll be good to go for 95% of most sailing conditions !!!!!!!
Forestay/backstay tension is important as it provides a properly tensioned structure for the jib/genoa to operate ... most sailmakers 'assume' that the forestay is at approx. 15% tension; and, the jib/genoa is designed and cut for this expected
tension in the forestay.
You adjust the backstay to this approximate 15% tension and the important forestay tension automatically 'reacts' to the backstay tension adjustment. Another way to state this is you adjust backstay tension to get the proper
forestay tension ..... then once this is set, you adjust ALL other rigging tensions.
Simple speak: Just follow the rig adjustment tensions in the 'order'
or sequence as described in this manual.
hope this helps.