Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
I am doctor and have no clue how this works, all I was told by the guy who we used to partner for developing our website was that I have to go to lets encrypt and do it myself. I have no clue how it is done, can anyone guide me please?
Sorry to say I am not sure we will be much help to you. We usually give advice to computer administrators to use specialized software to get a Let's Encrypt cert.
If you don't have these computer skills that will be very difficult. Did you try contacting your hosting company for help? Is it InMotion Hosting?
If your hosting service cannot help your best option is to find a website hosting service that does provide certs and other system admin on your behalf. There are many options for WordPress sites. Or, ask your prior partner for recommendations on people to help you.
To get an idea of how Let's Encrypt works visit below. If none of that makes sense to you we won't be much help.
Was he also the guy who fixed the certificate in the first place? If so, why didn't he leave detailed instructions?
It sounds like you're on some kind of hosted platform and usually you have limited access to everything.
From your certificate history at crt.sh | wellnestmd.com I can see you had a wildcard certificate previously (with a *. in the front) and that requires access to the DNS server.. And that's as far as I know not something WordPress can do and probably needs to be fixed by your hosting provider.
I agree with Mike that you probably need to contact InMotion Hosting.
I sincerely appreciate your response and will contact the previous web host immediately. We were moving onto a new company to host and build our website so the previous I believe "in motion" team did not hand over all the required data to me/owner.