You will only have great relationships when you are ready to take responsibility for yourself. Once you accept that the qualities of your thoughts and beliefs help to create the quality of your life then you are well on your way to going for and achieving whatever it is you want.
A positive approach keeps you motivated and enthusiastic and this energy always attracts fresh possibilities and new relationships; yes there really are many fish in the sea, you just have to get out there with your rod!
The negative view will create self-doubt and insecurity and an inability to take assertive action, so if a likely love interest does swim by it might be just too scary to bait your line and reel them in.
Whether your thoughts and beliefs are positive or negative will obviously have a great impact on the type of people you attract and the sort of relationship choices you make. An optimistic outlook always brings a feeling of hopefulness and confidence to any situation and this automatically open the door to new prospects in life (and love). It's so simple: negativity attracts negativity and positivity attracts positivity. So radiate whatever it is you want to attract. When you demonstrate enthusiasm and motivation you uplift the energy of those around you and draw similarly positive people into your orbit.
The type of relationships you attract depends entirely upon the type of energy you project.