You might be ADHD. Get a proper diagnosis. There are drugs to decrease the memory and concentration issues. HOWEVER, the side effects are scary and the drugs can be costly.
There are natural methods to improve quality of life. Exercise, eating well, sleeping enough. This may seem basic and silly but many people ignore these basics and suffer for it, then wondering why they feel so bad mentally and physically.
How do I know? My partner has ADHD, he was diagnosed at the ripe old age of 26 years old.

We believe many people likely suffer from it in variations of severity. He has been medicated and noticed a remarkable difference but it was costly and insurance did not cover it, not to mention the side effects listed are worrisome and there has not been enough long term medical reviews to indicate how it may affect long term health and longevity.
We cope very well with regular exercise, eating well and keeping regular sleep. It isn't always perfect, but striving for it makes it something achievable. Other than that, we try to find activities that do not involve ONLY watching TV or the internet (Basically staring at a screen too long - he can become very hyper-focused and play games for days if left to his own devices) - we go out, dance, read, etc.
For staying on top of things and remembering appointments and deadlines, he uses his smartphone to its full capacity. He CANNOT rely on his memory. He needs the alarms and reminders. As for memory, he has horrible short term memory but his long term memory is great - I know that seems like an oxymoron but it is true. It is as though his brain just hasn't filed it into the right compartments for him to pull the memory out at will until some time has passed.
Socializing is also important. This is more for emotional health. Family and friends on a regular basis keep us feeling good and remind us of the community and social circle we have to rely on.
Of course, everyone has varying symptoms and severity but most learn to cope and live very well. You NEED tools. Identify what helps and what doesnt. A notebook worked for him but he would misplace it (common for ADHD sufferers) so the phone is a better tried and true tool. Thank goodness for technology.
You CAN live a full enriching life. I know you feel hopeless and probably worthless alot of the time when these are things you cannot help and many people forget or do not understand - BUT it is okay! I am guilty of sometimes getting frustrated at my partner but have to remind myself that it is not his fault and none of his lapses are intentional or meant to be hurtful.
Find people who understand and can support you. Feeling alone will leave you getting depressed and worsening your condition and challenges. We met someone else who is also ADHD, spent most of her childhood being drugged with horrible medication that left her dazed most of the time, now she refuses to be medicated other than *ahem*weed*ahem* and is doing very very well (She has problems slowing down and often feels mentally and emotionally overloaded without the relaxant). My own partner is also in the works of starting his own business. They are both highly intelligent, but without the support they have and the tools and methods they have come up with to deal with their individual problems, they could not move forward.
It can be done. Look online for resources, communities and suggestions on how to better cope with your symptoms.
*hugs* Is all gooooood~