Seeking advice for long-term prone masturbation effects (ED / PE)

I’m a 24M. For most of my life (around 15 years), I engaged in prone-style self-stimulation (lying face-down). I did this frequently everyday and only recently learned that it may have potential long-term effects.

Currently, I’m dealing with:

• ED: trouble getting or maintaining rigidity despite mental arousal
• PE: this occurs during partnered intimacy and during non-prone self-stimulation and I can't last more than 20 seconds max

I’ve seen a urologist and was prescribed tadalafil 5mg daily for 3 months. This has significantly improved erection quality, and I’m now able to achieve full erections. However, I’m still experiencing super sensitivity and have no control over ejaculation.

Additional context:

• I do not use pornography
• Arousal is mainly fantasy-based
• I stopped proning completely
• I don't have access to sex therapists here

Since my erections are improving with tadalafil but I still have very poor ejaculatory control, would an SSRI such as sertraline be a reasonable treatment option?

I’m actively trying to improve my situation, but it’s been overwhelming and discouraging. If anyone has had similar experiences, medical insight, advice on treatment approaches, behavioral techniques, or realistic timelines for improvement, I’d really appreciate hearing from you.