aj, I feel you man. I had similar experiences and feelings and have been wanting to stop seeing SPs due to feeling lonely afterwards. My goal is also the same as yours, to have a meaningful relationship and not needing to spend money for temporary relief of pain/pleasure. It sounds like you've been through a lot, I would like to suggest a few things that really helped me recently regarding this exactly issue.
Everytime we go through some kind of trauma (your friend being a big one), we hold onto these negative feelings and shove everything down onto your subconscious, hoping to forget it consciously. Yet you hold onto all of these negative experiences and feelings and it prevents you from being and doing who you really want to be. For example, you may feel like you are very different from others and that you assume you have a hard time connecting with others or, may have some kind of society anxiety. I've also been through some horrendous experiences that caused a lot of anxiety and have been holding onto a whole bunch of shit unconsciously.
What really really helped me, and although I've learned this in the past, was the realization that you will never ever, ever be happy by getting something or someone. No matter who or what you get, you will always seek something else, we are programmed to think that we always need something to feel the emotion of being happy. If you get to the point where you realize getting someone to fill your void is not going to make you happy, and that your true "state" is actually happiness itself (think back to when you were a child, you were probably a lot happier than you are now), you will never have the feeling of needing someone or something to make you happy. It's easy and very cliche to say that you should always be happy without needing or wanting anything, but it's more complex than that. If you come from a place where you NEED something to feel the emotion of happiness, it's ALWAYS temporary, and this always leads to 2 states: being happy or unhappy. But if you come from a place of not NEEDING something or someone, you come from a place of abundance, and you will automatically be far more attractive to others as a person who is just happy being in their own shoes rather than someone who is desperate from affection. This doesn't mean you don't ever need money, love, or you should never go towards your goals because you don't NEED it, it just means you will approach these goals from a completely different place where you can achieve them far easily and happier.
This video really helped me realized that again, this guys been through a lot and explains it very well, and also shows how you can learn to let go of all your emotional baggage.
https://www.youtube.com/watch?v=3xxqg4PHg3M
Also if you have some specific emotions that you'd like to release, try EFT. Search EFT (and the emotion you are feeling) on youtube, there are plenty of videos to help you through them.
My life hasn't completely changed and I'm still working towards finding love etc, but I'm no longer coming from a place of scarcity, I no longer feel this void of needing someone to feel happy. I'm so much happier now than ever before, and I feel so much better when interacting with others now that I actually don't really care about the outcome. Even though I haven't yet completely healed from all of the trauma from the past, just KNOWING that this is true (everything I just talked about), has really helped me live a happier life overall. I'm a young professional that is doing extremely well in my career, and I absolutely love what I do. I'm focused on my career right now so I do ocassionally see SPs (for fun, not to fill a void as I'm doing well financially), I'm not a fan of wasting time on tinder. I agree with surferboy, a lot of the times escorts are actually cheaper than all the drinks and dinners you will spend on girls, plus saves you a lot of time. I'm not highly recommending that you continue to see SPs, and definitely do encourage you to find that love of your life as I'm seeking it just like you, but I also don't discourage seeing SPs when you can afford it just to keep your sex life going.