I looked up the definition of criminal harassment. The CPS website summarises it as follows:
"In this legal guidance, the term harassment is used to cover the 'causing alarm or distress' offences under section 2 of the Protection from Harassment Act 1997 as amended (PHA), and 'putting people in fear of violence' offences under section 4 of the PHA. The term can also include harassment by two or more defendants against an individual or harassment against more than one victim.
Although harassment is not specifically defined in section 7(2) of the PHA, it can include repeated attempts to impose unwanted communications and contact upon a victim in a manner that could be expected to cause distress or fear in any reasonable person.
A prosecution under section 2 or 4 requires proof of harassment. In addition, there must be evidence to prove the conduct was targeted at an individual, was calculated to alarm or cause him/her distress, and was oppressive and unreasonable.
Closely connected groups may also be subjected to 'collective' harassment. The primary intention of this type of harassment is not generally directed at an individual but rather at members of a group. This could include: members of the same family; residents of a particular neighbourhood; groups of a specific identity including ethnicity or sexuality, for example, the racial harassment of the users of a specific ethnic community centre; harassment of a group of disabled people; harassment of gay clubs; or of those engaged in a specific trade or profession."
It does seem to me that where you are putting up large graphic pictures of foetuses and graphic descriptions your intention must be to cause alarm and distress. Certainly if your conduct is of the type that Hygge describes, when you are haranguing woman who simply approach the clinic, you must meet the definition of harassment. This really is something the police need to deal with.
I believe in the US there have been occasions when people attending funeral have been protected from the attention of the Westboro Baptist Church by a cordon of legitimate protesters keeping them away. That wouldn't be practicable on a daily basis to protect people visiting abortion clinics, but it would be good if the occasional demonstration of that nature could be set up with a cordon of people surrounding the anti-abortion demonstration so that they couldn't be seen by those attending the clinic.