I think this is a very common problem for someone with Mars in Gemini. Mars is towards what and how do we direct our energy. Therefore, when it is in the sign of Gemini, the energy is directed sporadically. The person has a lot of different interests, and can get bored doing the same things over and over, leading to a decrease in focus and motivation. You said "I find it hard to stick to anything without feeling trapped and uninspired.", which is so classically Gemini. Based on this, I think you like (and need) variety.
However, Radinka, you are a triple Scorpio!!
Scorpio Sun, Moon, and Rising. Such a combination gives a lot of emotional intensity and passion. When you love something, you love it 150% and are dedicated. You are also highly perceptive. Therefore, I think your career interests have so far made a lot of sense (art, psychology, etc.).
Therefore, I do not think it will be hard for you to be dedicated and passionate about a job, so long as there is sufficient variety in it - so long as it keeps you learning and doing new things almost every day, and is related to emotional intensity, emotional expression, healing, and other Scorpio areas.
With Taurus in your 5th/6th house, art and gardening are very natural parts of your daily life and things you love to do. Taurus represents the senses, sensuality, art, earth, so it makes a lot of sense that it is either in your 5th house (house of recreation and passions), and your 6th (house of daily life and routine). So, it is quite possible to be part of your career, but it will be in your life regardless.
Can you re-upload your chart in Whole signs instead of Placidus? I don't find Placidus to be the most accurate chart system so I am unsure of what your houses can be. That will help glean a lot more insights. For example, 2nd house is the house of money, so that can be highly indicative of career. 10th house is also often considered a house of career and public reputation. 6th house is quite significant as well, as it shows your daily activities, your daily work. Looking at house rulers would help.
As far as whether being an artist is realistic or not, I think it can be. There are many different art-related careers, public art, graphic design, advertising, teaching art, art director, art administration, museum work, art therapy; There are many different possibilities.
I met the Brazilian contemporary artist Sandra Cinto once, and she was very inspiring to my view that art can be a realistic profession, in that she was hired to do public artwork for my university (designing the art for the buildings and such), but then her work is also showcased in international galleries, and then she is also an art professor because she studied art education in school. She said that she grew up very poor and in Brazil, so she never expected all of this to happen to her, but achieved it all through school. So I think that there are possibilities, generally.
Also, I am a beginner at reading charts, and a student myself, so take what I say with a grain of salt too. You know yourself best and will be able to evaluate it best for yourself.