Your problem is the making friends and the lack of confidence. Uni is supposed to help you find yourself. You need confidence in this dog-eat-dog world. You need to have some sort of charisma. Some people find it early in their their childhood, others not until after uni.
Might I suggest you try look for a part-time job? I have never really had a problem with confidence (unless I was surrounded with a group of cliques). But, when I had a job, it made me extra confident because I had to talk to randomers and face a lot of different people. This might be good for your self-esteem problem. No matter, which uni you'd go to - you will HAVE to put in the effort to make friends and maintain them. That is life. You get what you earn really. If you never made the effort to make friends during Freshers, then now - unfortunately, you are reaping those consequences.
A therapist isn't used for people who have mental health problems - that's usually for psychiatrists. Therapists are used for lots of reasons, if someone is feeling lonely, truamtized, fear, anxiety, stress, etc. I would recommend seeing one because they can help you with your confidence and give you some tricks and tips to help you.