While we acknowledge that 'blockages' to suppressed energetic negativity can also limit positive expression and experience, there's more to it than just that. To think that you can't create art until you become psychologically clear is a disempowering idea. Artists are notorious for emotional instability if not neurosis yet they still create works, and are in fact often motivated by unresolved subconscious issues that find their way into the art and become the power source that makes the art come alive.
Your first priority might be then to examine your attitude towards art-making. From the point of view of EC work, as well as general psychological enlightenment, the highest purpose of art is to reveal suppressed subconscious contents, both in the artist and the viewer. We invite our inner darkness to come forward and emerge in the art process. We are empowered by the inner darkness. As artists, we possess an extraordinary advantage in inner work that the ordinary person lacks. Art becomes a vital means for us to discover ourselves. Exactly how to do this is what I talk about in my book, EMOTION AND ART, which I would recommend highly.
For example, in the book I talk about how making art is inherently a manic-depressive experience, to which you have alluded. The artistic high is always followed by the depressive low. This is the dualistic nature of the human psyche. If you are not aware of this tendency, you can become trapped in it, running from the low with addictions and compulsions to try to get back to the creative high, or you just get discouraged. The key is to learn how to integrate both sides into a basically productive experience.
Then, there's the notion that one must 'express' something in the art in order to heal or get rid of it. This is another trap for the artist, because it implies that the negative subconscious which is emerging must be expelled instead of integrated. This is my take on why artists don't heal, even if they are producing. The key factor of acceptance is missing. Once the subconscious has emerged, it still must be processed using the EC steps in order to resolve. Simply becoming aware of it is not enough.
With regard to your personal situation, my guess is that your psychic energy is low so that you are unable to channel it into artistic creation. Raising your energy level is then another priority. You've recently been through some traumatic experiences, and these are probably suppressed and constitute an energy drain, so careful processing must be applied to them. The shame you talk about would be a starting point in EC meditative inner processing work. I usually consider shame a first-level emotion, and behind it is the core feeling that you must get to. Go into the shame, and see where it takes you. Let images come up and let them trigger other feelings, and apply the process.
I would caution you about thinking that you have inherited some kind of self-limiting tendency from your father. This would be blameful avoidance of responsibility, and can stop you in your tracks. We attract to ourselves influences including parents who coincide with the darkness and tendencies we bring into this life. They are not the prime cause. Take responsibility for yourself. That said, regressions concerning your father's influence on your inner child could be productive. There very well could be negative associations stored away that interfere with your creative output, but this would be highly personal, and you must discover them for yourself. In a regression, you envision yourself during your meditation at an early age with your father and invite any discordant experience to arise in your mind, and you process those feelings and/or include them in a painting or song you are creating.
To raise your energy and get your physical in shape, the best way I know of is a traditional regular meditative yoga practice, with breathwork, watching your diet and expenditure of sexual energy. Ejaculations are severely energy-draining.
To sum it up, you're really embarking on a life journey. Resolution is not going to come overnight, but if you establish a serious, dedicated inner practice, combined with an enlightened approach to your art, no question that over time you will see results. You can 'keep at it' when not feeling it to a certain extent, but if you don't have the energy, it's not going to work. Perhaps a new view of what art is supposed to do for you will ignite a fire.
https://www.emclear.com/EmotionAndArt.html