I don't think your problem is Jupiter as much - I think your "problem" (how ever you want to perceive it) is Venus. Even though it is exalted in Pisces, it is still in the 8th house that is quite a gloomy house. Venus is also pretty harshly aspected by both Jupiter and Mars and Moon. And to add to that, it is conjuncting Rahu, which is a very malefic planet.
Jupiter rules your 6th house of enemies and your Venus is square Jupiter. Venus is also the ruler for your 11th house.
I think that with your Venus placement, you are very idealistic about love and people, but when it is in conjunction with Rahu (malefic planet), it can cause problems in all relationships.
So in this life your biggest karmic lessons involve around relationships and how to be in one, how to balance it out, what to expect from people and how to love others. You also need to train your skills in Venusian things, like being diplomatic and considerate of others, how to be social and upkeep a social circle, how to relate to other people on a Venusian way (light, bubbly, charming, loving). People with this aspect need to learn a LOT about relationships and they usually make a lot of wrong choices in their youth, but will usually settle down late 30's or early 40's. The more they mature, their "taste" in people matures and their relationships get better.
When Rahu's obsessive energy is conjunction with Venus and what it does, is that the Venus energy is amplified. Sometimes people with this placement can be quite promiscious and they need a lot of attention from many people and they may feel like one person's attention especially in a relationship is not enough and this can create drama. These people can also get a bit too obsessive about their relationships to the point of smothering their lovers, which leads that their partner wants more space and these people feel like they have been rejected and because they have such deep emotions, they feel so rejected that they may want to cheat in order to get back. So with this energy, you might have a tendency to go to extremes and this extreme behaviour and thought patterns cause extreme actions also in other people around you because what we send out, we get back.
This aspect can also mean that person gets over obsessive over some qualities in a person. Also this can mean that these people attract and are interested in partners that are sexually (or mentally) exciting and dangerous but they other qualities are not compatible with the person at all - but still they might go with them, cause it is so exciting! Their taste in relationships can be a bit "odd" and eccentric. Sometimes women with this aspect are very beautiful and very sexual and like to show that and that definitely attracts the wrong kind of attention and people with not-so-pure intentions. It is also important in relationships to not try to control the relationship with sex and manipulate with sexuality. Because you have some favourable aspects from Saturn to your Venus, it might be that you do not posses these qualities as much, but I'll just put it out there so you'll get an idea of the type of energy that is present.
Sometimes this aspects shows in a way that person really is a loner and they are so scared of relationships and it is so unknown to them that they just cancel themselves out of the game completely. So it tends to be one or the other - completely obsessiveness or completely off.
So this is definitely a position that needs some working and conscious work, but if you do it, you are definitely able to have fulfilling happy relationships.